Organometallic compound, organic light-emitting device including organometallic compound, and diagnostic composition including organometallic compound

ABSTRACT

An organometallic compound represented by Formula 1: 
     
       
         
         
             
             
         
       
         
         
           
             wherein, in Formula 1, groups and variables are the same as described in the specification.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Korean Patent Application No. 10-2016-0146906, filed on Nov. 4, 2016, in the Korean Intellectual Property Office, and all the benefits accruing therefrom under 35 U.S.C. § 119, the content of which is incorporated herein in its entirety by reference.

BACKGROUND 1. Field

The present disclosure relates to an organometallic compound, an organic light-emitting device including the organometallic compound, and a diagnostic composition including the organometallic compound.

2. Description of the Related Art

Organic light-emitting devices (OLEDs) are self-emission devices that have wide viewing angles, exhibit excellent driving voltage and response speed characteristics, and produce full-color images.

Typical OLEDs include an anode, a cathode, and an organic layer disposed between the anode and the cathode, wherein the organic layer includes an emission layer. A hole transport region may be disposed between the anode and the emission layer, and an electron transport region may be disposed between the emission layer and the cathode. Holes provided from the anode may move toward the emission layer through the hole transport region, and electrons provided from the cathode may move toward the emission layer through the electron transport region. The holes and the electrons recombine in the emission layer to produce excitons. The excitons may transition from an excited state to a ground state, thereby generating light.

Further, light-emitting compounds, e.g., phosphorescence-emitting compounds, can also be used to monitor, sense, or detect biological materials, including a variety of cells and proteins.

Various types of organic light emitting devices are known. However, there still remains a need in OLEDs having low driving voltage, high efficiency, high brightness, and long lifespan.

SUMMARY

Provided are an organometallic compound, an organic light-emitting device including the organometallic compound, and a diagnostic composition including the organometallic compound.

Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments.

According to an aspect of an embodiment, an organometallic compound is represented by Formula 1:

wherein, in Formula 1,

M₁₁ is selected from beryllium (Be), magnesium (Mg), aluminum (Al), calcium (Ca), titanium (Ti), manganese (Mn), cobalt (Co), copper (Cu), zinc (Zn), gallium (Ga), germanium (Ge), zirconium (Zr), ruthenium (Ru), rhodium (Rh), palladium (Pd), silver, (Ag), rhenium (Re), platinum (Pt), and gold (Au),

T₁₁ is selected from oxygen (O) and sulfur (S),

p11 is selected from 0 and 1; provided that when p11 is 0, *-(T₁₁)_(p11)-*′ is a single bond,

T₁₂ to T₁₄ are each independently selected from nitrogen (N) and carbon (C), when p11 is 0, a bond between X₁₁ and M₁₁ is a covalent bond or a coordinate bond; when p11 is 1, provided that a bond between T₁₁ and M₁₁ is a covalent bond,

i) when p11 is 0, two bonds selected from a bond between X₁₁ and M₁₁, a bond between T₁₂ and M₁₁, a bond between T₁₃ and M₁₁, and a bond between T₁₄ and M₁₁ may each be a covalent bond, and the other two bonds may each be a coordinate bond; or

ii) when p11 is 1, two bonds selected from a bond between T₁₁ and M₁₁, a bond between T₁₂ and M₁₁, a bond between T₁₃ and M₁₁, and a bond between T₁₄ and M₁₁ may each be a covalent bond, and the other two bonds may each be a coordinate bond,

X₁₁ to X₁₈ are each independently selected from C and N,

a bond between X₁₁ and X₁₂, a bond between X₁₃ and T₁₂, a bond between X₁₃ and Y₁₁, a bond between T₁₂ and X₁₄, a bond between X₁₄ and N, a bond between X₁₄ and X₁₅, a bond between Y₁₁ and N, a bond between X₁₆ and T₁₃, a bond between T₁₃ and X₁₇, and a bond between X₁₈ and T₁₄ are each independently selected from a single bond and a double bond,

A₁₁, A₁₃, and A₁₄ are each independently selected from a C₅-C₃₀ carbocyclic group and a C₁-C₃₀ heterocyclic group,

A₁₂ and A₁₅ are each independently selected from a C₁-C₃₀ heterocyclic group,

L₁₁ to L₁₃ are each independently selected from *—O—*′, *—S—*′, *—[C(R₁₅)(R₁₆)]_(k11)—*40 , *—C(R₁₅)═*′, *═C(R₁₅)—*′, *—C(R₁₅)═C(R₁₆)—*′, *—C(═O)—*′, *—C(═S)—*′, *—C≡C—*′, *—N(R₁₅)—*′, *—P(R₁₅)—*′, *—[Si(R₁₅)(R₁₆)]_(k11)—*′, and *—P(R₁₅)(R₁₆)—*′,

R₁₅ and R₁₆ may optionally be bound via a first linking group to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group,

k11 is selected from 1 and 2,

a11 to a13 are each independently selected from 0, 1, 2, and 3; when a11 is 0, *-(L₁₁)_(a11)-*′ is a single bond; when a12 is 0, *-(L₁₂)_(a12)-*′ is a single bond; when a13 is 0, *-(L₁₃)_(a13)-*′ is a single bond,

Y₁₁ is selected from N(R₁₇), N, C(R₁₇)(R₁₈), C(R₁₇), Si(R₁₇)(R₁₈), Si(R₁₇), and C(═O),

R₁₇ and R₁₈ may optionally be bound via a second linking group to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group,

L₁₄ to L₁₇ are each independently selected from a substituted or unsubstituted C₅-C₃₀ carbocyclic group and a substituted or unsubstituted C₁-C₃₀ heterocyclic group, al 4 to al 7 are each independently selected from 0, 1, 2, 3, 4, and 5,

R₁₁ to R₁₈ are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, —SF₅, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted C₁-C₆₀ heteroaryloxy group, a substituted or unsubstituted C₁-C₆₀ heteroarylthio group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), and —P(═O)(Q₈)(Q₉),

b11 to b14 are each independently selected from 1, 2, 3, 4, and 5,

n11 to n14 are each independently selected from 0, 1, 2, 3, 4, and 5,

two adjacent groups R₁₁ of a plurality of groups R₁₁ may optionally be bound to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group,

two adjacent groups R₁₂ of a plurality of groups R₁₂ may optionally be bound to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group,

two adjacent groups R₁₃ of a plurality of groups R₁₃ may optionally be bound to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group,

two adjacent groups R₁₄ of a plurality of groups R₁₄ may optionally be bound to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group,

at least two of R₁₁ to R₁₄, wherein the at least two of R₁₁ to R₁₄ are adjacent to each other, may optionally be bound to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group,

wherein Q₁ to Q₉ are each independently selected from hydrogen; deuterium; —F; —Cl; —Br; —I; a hydroxyl group; a cyano group; a nitro group; an amidino group; a hydrazine group; a hydrazone group; a carboxylic acid group or a salt thereof; a sulfonic acid group or a salt thereof; a phosphoric acid group or a salt thereof; a C₁-C₆₀ alkyl group; a C₁-C₆₀ alkyl group substituted with at least one of deuterium, a C₁-C₆₀ alkyl group, and a C₆-C₆₀ aryl group; a C₂-C₆₀ alkenyl group; a C₂-C₆₀ alkynyl group; a C₁-C₆₀ alkoxy group; a C₃-C₁₀ cycloalkyl group; a C₁-C₁₀ heterocycloalkyl group; a C₃-C₁₀ cycloalkenyl group; a C₁-C₁₀ heterocycloalkenyl group; a C₆-C₆₀ aryl group; a C₆-C₆₀ aryl group substituted with at least one of deuterium, a C₁-C₆₀ alkyl group, and a C₆-C₆₀ aryl group; a C₆-C₆₀ aryloxy group; a C₆-C₆₀ arylthio group; a C₁-C₆₀ heteroaryl group; a monovalent non-aromatic condensed polycyclic group; and a monovalent non-aromatic condensed heteropolycyclic group, and

* and *′ each independently indicate a binding site to an adjacent atom.

According to an aspect of another embodiment, an organic light-emitting device includes:

a first electrode;

a second electrode; and

an organic layer disposed between the first electrode and the second electrode,

wherein the organic layer includes an emission layer and at least one organometallic compound represented by Formula 1.

According to an aspect of another embodiment, there is provided a diagnostic composition including at least one organometallic compound represented by Formula 1.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic cross-sectional view of an organic light-emitting device according to an embodiment.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. In this regard, the present embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the embodiments are merely described below, by referring to the figures, to explain aspects. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list.

It will be understood that when an element is referred to as being “on” another element, it can be directly in contact with the other element or intervening elements may be present therebetween. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present.

It will be understood that, although the terms first, second, third etc. may be used herein to describe various elements, components, regions, layers, and/or sections, these elements, components, regions, layers, and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, or section from another element, component, region, layer, or section. Thus, a first element, component, region, layer, or section discussed below could be termed a second element, component, region, layer, or section without departing from the teachings of the present embodiments.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

The term “or” means “and/or.” It will be further understood that the terms “comprises” and/or “comprising,” or “includes” and/or “including” when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this general inventive concept belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Exemplary embodiments are described herein with reference to cross section illustrations that are schematic illustrations of idealized embodiments. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments described herein should not be construed as limited to the particular shapes of regions as illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, a region illustrated or described as flat may, typically, have rough and/or nonlinear features. Moreover, sharp angles that are illustrated may be rounded. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the precise shape of a region and are not intended to limit the scope of the present claims.

“About” or “approximately” as used herein is inclusive of the stated value and means within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art, considering the measurement in question and the error associated with measurement of the particular quantity (i.e., the limitations of the measurement system). For example, “about” can mean within one or more standard deviations, or within ±30%, 20%, 10%, 5% of the stated value.

An organometallic compound represented by Formula 1 may be neutral, and may not include ion pairs of cations and anions:

In Formula 1, M₁₁ may be selected from beryllium (Be), magnesium (Mg), aluminum (Al), calcium (Ca), titanium (Ti), manganese (Mn), cobalt (Co), copper (Cu), zinc (Zn), gallium (Ga), germanium (Ge), zirconium (Zr), ruthenium (Ru), rhodium (Rh), palladium (Pd), silver, (Ag), rhenium (Re), platinum (Pt), and gold (Au).

In some embodiments, in Formula 1, M₁₁ may be platinum, but embodiments are not limited thereto.

In Formula 1, T₁₁ may be selected from O and S.

In Formula 1, p11 may be selected from 0 and 1; provided that when p11 is 0, *-(T₁₁)_(p1)-*′ may be a single bond.

In Formula 1, T₁₂ to T₁₄ may each independently be selected from nitrogen (N) and carbon (C).

In Formula 1, when p11 is 0, a bond between X₁₁ and M₁₁ may be a covalent bond or a coordinate bond; provided that when p11 is 1, a bond between T₁₁ and M₁₁ may be a covalent bond.

In Formula 1, i) when p11 is 0, two bonds selected from of a bond between X₁₁ and M₁₁, a bond between T₁₂ and M₁₁, a bond between T₁₃ and M₁₁, and a bond between T₁₄ and M₁₁ may each be a covalent bond, and the other two bonds may each be a coordinate bond; or

ii) when p11 is 1, two bonds selected from a bond between T₁₁ and M₁₁, a bond between T₁₂ and M₁₁, a bond between T₁₃ and M₁₁, and a bond between T₁₄ and M₁₁ may each be a covalent bond, and the other two bonds may each be a coordinate bond.

In some embodiments, in Formula 1, p11 may be 1, and a bond between T₁₁ and M₁₁ may be a covalent bond, but embodiments are not limited thereto.

In some embodiments, in Formula 1, when p11 is 0, X₁₁ and T₁₂ may each be C, T₁₃ and T₁₄ may each be N, a bond between X₁₁ and M₁₁ and a bond between T₁₂ and M₁₁ may each be a covalent bond, and a bond between T₁₃ and M₁₁ and a bond between T₁₄ and M₁₁ may each be a coordinate bond;

when p11 is 0, X₁₁ and T₁₄ may each be C, T₁₂ and T₁₃ may each be N, a bond between X₁₁ and M₁₁ and a bond between T₁₄ and M₁₁ may each be a covalent bond, and a bond between T₁₂ and M₁₁ and a bond between T₁₃ and M₁₁ may each be a coordinate bond;

when p11 is 0, X₁₁ and T₁₃ may each be C, T₁₂ and T₁₄ may each be N, a bond between X₁₁ and M₁₁ and a bond between T₁₃ and M₁₁ may each be a covalent bond, and a bond between T₁₂ and M₁₁ and a bond between T₁₄ and M₁₁ may each be a coordinate bond;

when p11 is 0, X₁₁ and T₁₂ may each be N, T₁₃ and T₁₄ may each be C, a bond between X₁₁ and M₁₁ and a bond between T₁₂ and M₁₁ may each be a coordinate bond, and a bond between T₁₃ and M₁₁ and a bond between T₁₄ and M₁₁ may each be a covalent bond;

when p11 is 0, X₁₁ and T₁₄ may each be N, T₁₂ and T₁₃ may each be C, a bond between X₁₁ and M₁₁ and a bond between T₁₄ and M₁₁ may each be a coordinate bond, and a bond between T₁₂ and M₁₁ and a bond between T₁₃ and M₁₁ may each be a covalent bond;

when p11 is 0, X₁₁ and T₁₃ may each be N, T₁₂ and T₁₄ may each be C, a bond between X₁₁ and M₁₁ and a bond between T₁₃ and M₁₁ may each be a coordinate bond, and a bond between T₁₂ and M₁₁ and a bond between T₁₄ and M₁₁ may each be a covalent bond;

when p11 is 1, T₁₂ may be C, T₁₃ and T₁₄ may each be N, a bond between T₁₁ and M₁₁ and a bond between T₁₂ and M₁₁ may each be a covalent bond, and a bond between T₁₃ and M₁₁ and a bond between T₁₄ and M₁₁ may each be a coordinate bond;

when p11 is 1, T₁₄ may be C, T₁₂ and T₁₃ may each be N, a bond between T₁₁ and M₁₁ and a bond between T₁₄ and M₁₁ may each be a covalent bond, and a bond between T₁₂ and M₁₁ and a bond between T₁₃ and M₁₁ may each be a coordinate bond; or

when p11 is 1, T₁₃ may be C, T₁₂ and T₁₄ may each be N, a bond between T₁₁ and M₁₁ and a bond between T₁₃ and M₁₁ may each be a covalent bond, and a bond between T₁₂ and M₁₁ and a bond between T₁₄ and M₁₁ may each be a coordinate bond, but embodiments are not limited thereto.

In some embodiments, in Formula 1, when p11 is 1, T₁₂ may be C, T₁₃ and T₁₄ may each be N, a bond between T₁₁ and M₁₁ and a bond between T₁₂ and M₁₁ may each be a covalent bond, and a bond between T₁₃ and M₁₁ and a bond between T₁₄ and M₁₁ may each be a coordinate bond;

when p11 is 1, T₁₄ may be C, T₁₂ and T₁₃ may each be N, a bond between T₁₁ and M₁₁ and a bond between T₁₄ and M₁₁ may each be a covalent bond, and a bond between T₁₂ and M₁₁ and a bond between T₁₃ and M₁₁ may each be a coordinate bond; or

when p11 is 1, T₁₃ may be C, T₁₂ and T₁₄ may each be N, a bond between T₁₁ and M₁₁ and a bond between T₁₃ and M₁₁ may each be a covalent bond, and a bond between T₁₂ and M₁₁ and a bond between T₁₄ and M₁₁ may each be a coordinate bond, but embodiments are not limited thereto.

In Formula 1, X₁₁ to X₁₈ may each independently be selected from N and C.

In some embodiments, in Formula 1, X₁₂ to X₁₈ may each be C, but embodiments are not limited thereto.

In Formula 1, a bond between X₁₁ and X₁₂, a bond between X₁₃ and T₁₂, a bond between X₁₃ and Y₁₁, a bond between T₁₂ and X₁₄, a bond between X₁₄ and N, a bond between X₁₄ and X₁₅, a bond between Y₁₁ and N, a bond between X₁₆ and T₁₃, a bond between T₁₃ and X₁₇, and a bond between X₁₈ and T₁₄ may each independently be a single bond or a double bond.

In Formula 1, A₁₁, A₁₃, and A₁₄ may each independently be selected from a C₅-C₃₀ carbocyclic group and a C₁-C₃₀ heterocyclic group, and

A₁₂ and A₁₅ may each independently be selected from a C₁-C₃₀ heterocyclic group.

In Formula 1, A₁₅ may be a 5-membered ring formed of N, Y₁₁, X₁₃, T₁₂, and X₁₄.

In some embodiments, in Formula 1, A₁₁, A₁₃, and A₁₄ may each independently be selected from a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, a triphenylene group, a pyrene group, a chrysene group, a cyclopentadiene group, a 1,2,3,4-tetrahydronaphthalene group, a furan group, a thiophene group, a silole group, an indene group, a fluorene group, an indole group, a carbazole group, a benzofuran group, a dibenzofuran group, a benzothiophene group, a dibenzothiophene group, a benzosilole group, a dibenzosilole group, an indenopyridine group, an indolopyridine group, a benzofuropyridine group, a benzothienopyridine group, a benzosilolopyridine group, an indenopyrimidine group, an indolopyrimidine group, a benzofuropyrimidine group, a benzothienopyrimidine group, a benzosilolopyrimidine group, a dihydropyridine group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a phenanthroline group, a pyrrole group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, a thiazole group, an isothiazole group, an oxadiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzothiazole group, a benzoxadiazole group, a benzothiadiazole group, a 5,6,7,8-tetrahydroisoquinoline group, and a 5,6,7,8-tetrahydroquinoline group, and

A₁₂ and A₁₅ may each independently be selected from an indole group, a carbazole group, an indenopyridine group, an indolopyridine group, a benzofuropyridine group, a benzothienopyridine group, a benzosilolopyridine group, a dihydropyridine group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a phenanthroline group, a pyrrole group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, a thiazole group, an isothiazole group, an oxadiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzothiazole group, a benzoxadiazole group, a benzothiadiazole group, a 5,6,7,8-tetrahydroisoquinoline group, and a 5,6,7,8-tetrahydroquinoline group, but embodiments are not limited thereto.

In some embodiments, in Formula 1, A₁₁, A₁₃, and A₁₄ ma each independently be selected from a benzene group, a naphthalene group, a cyclopentadiene group, a 1,2,3,4-tetrahydronaphthalene group, a furan group, a thiophene group, a silole group, an indene group, a fluorene group, an indole group, a carbazole group, a benzofuran group, a dibenzofuran group, a benzothiophene group, a dibenzothiophene group, a benzosilole group, a dibenzosilole group, an indenopyridine group, an indolopyridine group, a benzofuropyridine group, a benzothienopyridine group, a benzosilolopyridine group, an indenopyrimidine group, an indolopyrimidine group, a benzofuropyrimidine group, a benzothienopyrimidine group, a benzosilolopyrimidine group, a dihydropyridine group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a pyrrole group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, a thiazole group, an isothiazole group, an oxadiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzothiazole group, a benzoxadiazole group, a benzothiadiazole group, a 5,6,7,8-tetrahydroisoquinoline group, and a 5,6,7,8-tetrahydroquinoline group, and

A₁₂ and A₁₅ may each independently be selected from an indole group, a carbazole group, an indenopyridine group, an indolopyridine group, a benzofuropyridine group, a benzothienopyridine group, a benzosilolopyridine group, a dihydropyridine group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a pyrrole group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, a thiazole group, an isothiazole group, an oxadiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzothiazole group, a benzoxadiazole group, a benzothiadiazole group, a 5,6,7,8-tetrahydroisoquinoline group, and a 5,6,7,8-tetrahydroquinoline group, but embodiments are not limited thereto.

In some embodiments, in Formula 1, A₁₁, A₁₃, and A₁₄ may each independently be selected from a benzene group, a naphthalene group, a 1,2,3,4-tetrahydronaphthalene group, a fluorene group, a dibenzofuran group, a dibenzothiophene group, a benzofuropyridine group, a benzothienopyridine group, a benzofuropyrimidine group, a benzothienopyrimidine group, a dihydropyridine group, a pyridine group, a pyrimidine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a pyrrole group, a pyrazole group, an imidazole group, a triazole group, a benzimidazole group, a 5,6,7,8-tetrahydroisoquinoline group, and a 5,6,7,8-tetrahydroquinoline group, and

A₁₂ and A₁₅ may each independently be selected from a dihydropyridine group, a pyridine group, a pyrimidine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a pyrrole group, a pyrazole group, an imidazole group, a triazole group, a 5,6,7,8-tetrahydroisoquinoline group, and a 5,6,7,8-tetrahydroquinoline group, but embodiments are not limited thereto.

In some embodiments, in Formula 1, A₁₁, A₁₃, and A₁₄ may each independently be selected from a benzene group, a naphthalene group, a 1,2,3,4-tetrahydronaphthalene group, a dibenzofuran group, a dibenzothiophene group, a benzofuropyridine group, a benzothienopyridine group, a benzofuropyrimidine group, a benzothienopyrimidine group, a dihydropyridine group, a pyridine group, a quinoline group, an isoquinoline group, a pyrrole group, an imidazole group, a benzimidazole group, a 5,6,7,8-tetrahydroisoquinoline group, and a 5,6,7,8-tetrahydroquinoline group, and

A₁₂ and A₁₅ may each independently be selected from a dihydropyridine group, a pyridine group, a quinoline group, an isoquinoline group, a pyrrole group, an imidazole group, a 5,6,7,8-tetrahydroisoquinoline group, and a 5,6,7,8-tetrahydroquinoline group, but embodiments are not limited thereto.

In an embodiment, in Formula 1, a cyclometalated ring formed of A₁₅, A₁₂, A₁₃, and M₁₁ may be a 6-membered ring, a 7-membered ring, or an 8-membered ring.

In an embodiment, in Formula 1, a cyclometalated ring formed of A₁₅, A₁₂, A₁₃, and M₁₁ may be a 6-membered ring.

In Formula 1, L₁₁ to L₁₃ may each independently be selected from *—O—*′, *—S—*′, *—[C(R₁₅)(R₁₆)]_(k11)—*40 , *—C(R₁₅)═*′, *═C(R₁₅)—*′, *—C(R₁₅)═C(R₁₆)—*′, *—C(═O)—*′, *—C(═S)—*′, *—C≡C—*′, *—N(R₁₅)—*′, *—P(R₁₅)—*′, *—[Si(R₁₅)(R₁₆)]_(k11)—*′, and *—P(R₁₅)(R₁₆)—*′, * and *′ may each independently indicate a binding site to an adjacent atom, R₁₅ and R₁₆ may optionally be bound via a first linking group to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group, and k11 may be selected from 1 and 2. R₁₅ and R₁₆ may be the same as those described herein.

In some embodiments, in Formula 1, L₁₁ to L₁₃ may each independently be selected from *—O—*′, *—S—*′, *—[C(R₁₅)(R₁₆)_(k11)—*′, *—N(R₁₅)—*′, *—[Si(R₁₅)(R₁₆)]_(k11)—*′, and *—P(R₁₅)(R₁₆)—*′, and

* and *′ may each independently indicate a binding site to an adjacent atom, but embodiments are not limited thereto.

In some embodiments, in Formula 1, L₁₁ to L₁₃ may each independently be selected from *—C(R₁₅)(R₁₆)—*′, *—Si(R₁₅)(R₁₆)—*′, and *—P(R₁₅)(R₁₆)—*′,

R₁₅ and R₁₆ may optionally be bound via the first linking group,

the first linking group may be selected from a single bond, *—O—*′, *—S—*′, *—[C(R₁₉)(R₂₀)]_(k12)—*′, *—C(R₁₉)═*′, *═C(R₁₉)—*′, *—C(R₁₉)═C(R₂₀)—*′, *—C(═O)—*′, *—C(═S)—*′, *—C≡C—*′, *—N(R₁₉)—*′, *—P(R₁₉)—*′, *—[Si(R₁₉)(R₂₀)]_(k12)—*′, and *—P(R₁₉)(R₂₀)—*′,

R₁₉ and R₂₀ may each independently be substantially the same as R₁₅,

k12 may be substantially the same as k11, and

* and *′ may each independently indicate a binding site to an adjacent atom, but embodiments are not limited thereto.

In Formula 1, a11 to a13 may each independently be selected from 0, 1, 2, and 3; when a11 is 0, *-(L₁₁)_(a11)-*′ may be a single bond; when a12 is 0, *-(L₁₂)_(a12)-*′ may be a single bond; when a13 is 0, *-(L₁₃)_(a13)-*′ may be a single bond.

In some embodiments, in Formula 1, a11 to a13 may each independently be selected from 0 and 1, but embodiments are not limited thereto.

In some embodiments, in Formula 1, a sum of a11 to a13 may be 1, but embodiments are not limited thereto.

In some embodiments, in Formula 1, a11 to a13 may each be 0, but embodiments are not limited thereto.

In Formula 1, Y₁₁ may be selected from N(R₁₇), N, C(R₁₇)(R₁₈), C(R₁₇), Si(R₁₇)(R₁₈), Si(R₁₇), and C(═O), R₁₇ and R₁₈ may optionally be bound via a second linking group to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group, and R₁₇ and R₁₈ may be the same as those described herein.

In some embodiments, in Formula 1, Y₁₁ may be selected from N and C(R₁₇), but embodiments are not limited thereto.

In some embodiments, in Formula 1, Y₁₁ may be C(R₁₇), but embodiments are not limited thereto.

In some embodiments, in Formula 1, the second linking group may be a single bond, *—O—*′, *—S—*′, *—[C(R₁₉)(R₂₀)]_(k12)—*′, *—C(R₁₉)═*′, *═C(R₁₉)—*′, *—C(R₁₉)═C(R₂₀)—*′, *—C(═O)—*′, *—C(═S)—*40 , *—C≡C—*′, *—N(R₁₉)—*′, *—P(R₁₉)—*′, *—[Si(R₁₉)(R₂₀)]_(k12)—*', and *—P(R₁₉)(R₂₀)—*′,

R₁₉ and R₂₀ may each independently be substantially the same as R₁₅,

k12 may be substantially the same as k11, and

* and *′ may each independently indicate a binding site to an adjacent atom, but embodiments are not limited thereto.

In Formula 1, L₁₄ to L₁₇ may each independently be selected from a substituted or unsubstituted C₅-C₃₀ carbocyclic group and a substituted or unsubstituted C₁-C₃₀ heterocyclic group.

In some embodiments, in Formula 1, L₁₄ to L₁₇ may each independently be selected from a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, a triphenylene group, a pyrene group, a chrysene group, a cyclopentadiene group, a furan group, a thiophene group, a silole group, an indene group, a fluorene group, an indole group, a carbazole group, a benzofuran group, a dibenzofuran group, a benzothiophene group, a dibenzothiophene group, a benzosilole group, a dibenzosilole group, an indenopyridine group, an indolopyridine group, a benzofuropyridine group, a benzothienopyridine group, a benzosilolopyridine group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a phenanthroline group, a pyrrole group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, a thiazole group, an isothiazole group, an oxadiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzothiazole group, a benzoxadiazole group, and a benzothiadiazole group; and

a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, a triphenylene group, a pyrene group, a chrysene group, a cyclopentadiene group, a furan group, a thiophene group, a silole group, an indene group, a fluorene group, an indole group, a carbazole group, a benzofuran group, a dibenzofuran group, a benzothiophene group, a dibenzothiophene group, a benzosilole group, a dibenzosilole group, an indenopyridine group, an indolopyridine group, a benzofuropyridine group, a benzothienopyridine group, a benzosilolopyridine group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a phenanthroline group, a pyrrole group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, a thiazole group, an isothiazole group, an oxadiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzothiazole group, a benzoxadiazole group, and a benzothiadiazole group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, a triazinyl group, a fluorenyl group, a dimethylfluorenyl group, a diphenylfluorenyl group, a carbazolyl group, a phenylcarbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a dimethyldibenzosilolyl group, a diphenyldibenzosilolyl group, —N(Q₃₁)(Q₃₂), —Si(Q₃₃)(Q₃₄)(Q₃₅), —B(Q₃₆)(Q₃₇), and —P(═O)(Q₃₈)(Q₃₉),

wherein Q₃₁ to Q₃₉ may each independently be selected from

—CH₃, —CD₃, —CD₂H, —CDH₂, —CH₂CH₃, —CH₂CD₃, —CH₂CD₂H, —CH₂CDH₂, —CHDCH₃, —CHDCD₂H, —CHDCDH₂, —CHDCD₃, —CD₂CD₃, —CD₂CD₂H, and —CD₂CDH₂;

an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, and a naphthyl group; and an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, and a naphthyl group, each substituted with at least one selected from deuterium, a C₁-C₁₀ alkyl group, and a phenyl group,

but embodiments are not limited thereto.

In some embodiments, in Formula 1, L₁₄ to L₁₇ may each independently be selected from a benzene group, a pyridine group, a pyrimidine group, and a triazine group; and

a benzene group, a pyridine group, a pyrimidine group, and a triazine group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a pyridinyl group and a pyrimidinyl group, —N(Q₃₁)(Q₃₂), —Si(Q₃₃)(Q₃₄)(Q₃₅), —B(Q₃₆)(Q₃₇), and —P(═O)(Q₃₈)(Q₃₉),

wherein Q₃₁ to Q₃₉ may each independently be selected from

—CH₃, —CD₃, —CD₂H, —CDH₂, —CH₂CH₃, —CH₂CD₃, —CH₂CD₂H, —CH₂CDH₂, —CHDCH₃, —CHDCD₂H, —CHDCDH₂, —CHDCD₃, —CD₂CD₃, —CD₂CD₂H, and —CD₂CDH₂;

an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, and a naphthyl group; and

an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, and a naphthyl group, each substituted with at least one selected from deuterium, a C₁-C₁₀ alkyl group, and a phenyl group, but embodiments are not limited thereto.

In Formula 1, al 4 to al 7 may respectively indicate numbers of L₁₄ to L₁₇, which may each independently be selected from 0, 1, 2, 3, 4, and 5. In Formula 1, when a14 is 0, *-(L₁₄)_(a14)-*′ may be a single bond; and when a14 is 2 or greater, at least two groups L₁₄ may be identical to or different from each other. a15 to a17 may each be substantially the same as a14.

In some embodiments, in Formula 1, a14 to a17 may each independently be selected from 0 and 1, but embodiments are not limited thereto.

In Formula 1, R₁₁ to R₁₈ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, —SF₅, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted C₁-C₆₀hetero aryloxy group, a substituted or unsubstituted C₁-C₆₀hetero arylthio group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), and —P(═O)(Q₈)(Q₉),

wherein Q₁ to Q₉ may each independently be selected from hydrogen; deuterium; —F; —Cl; —Br; —I; a hydroxyl group; a cyano group; a nitro group; an amidino group; a hydrazine group; a hydrazone group; a carboxylic acid group or a salt thereof; a sulfonic acid group or a salt thereof; a phosphoric acid group or a salt thereof; a C₁-C₆₀ alkyl group; a C₁-C₆₀ alkyl group substituted with at least one of deuterium, a C₁-C₆₀ alkyl group, and a C₆-C₆₀ aryl group; a C₂-C₆₀ alkenyl group; a C₂-C₆₀ alkynyl group; a C₁-C₆₀ alkoxy group; a C₃-C₁₀ cycloalkyl group; a C₁-C₁₀ heterocycloalkyl group; a C₃-C₁₀ cycloalkenyl group; a C₁-C₁₀ heterocycloalkenyl group; a C₆-C₆₀ aryl group; a C₆-C₆₀ aryl group substituted with at least one of deuterium, a C₁-C₆₀ alkyl group, and a C₆-C₆₀ aryl group; a C₆-C₆₀ aryloxy group; a C₆-C₆₀ arylthio group; a C₁-C₆₀ heteroaryl group; a monovalent non-aromatic condensed polycyclic group; and a monovalent non-aromatic condensed heteropolycyclic group.

In some embodiments, in Formula 1, R₁₁ to R₁₈ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, —SF₅, a C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group;

a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₁₀ alkyl group, a cyclopentyl group, a cyclopentyl group substituted with deuterium, a cyclohexyl group, a cyclohexyl group substituted with deuterium, a cycloheptyl group, a cycloheptyl group substituted with deuterium, a cyclooctyl group, a cyclooctyl group substituted with deuterium, a bicyclo[2.2.1]heptanyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a naphthyl group, a pyridinyl group, and a pyrimidinyl group;

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a bicyclo[2.2.1]heptanyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a naphthyl group, a lluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, and an imidazopyrimidinyl group;

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a bicyclo[2.2.1]heptanyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a naphthyl group, a lluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, and an imidazopyrimidinyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclopentyl group substituted with deuterium, a cyclohexyl group, a cyclohexyl group substituted with deuterium, a cycloheptyl group, a cycloheptyl group substituted with deuterium, a cyclooctyl group, a cyclooctyl group substituted with deuterium, a bicyclo[2.2.1]heptanyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, and —Si(Q₃₃)(Q₃₄)(Q₃₅); and

—N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), and —P(═O)(Q₈)(Q₉),

wherein Q₁ to Q₉ and Q₃₃ to Q₃₅ may each independently be selected from

—CH₃, —CD₃, —CD₂H, —CDH₂, —CH₂CH₃, —CH₂CD₃, —CH₂CD₂H, —CH₂CDH₂, —CHDCH₃, —CHDCD₂H, —CHDCDH₂, —CHDCD₃, —CD₂CD₃, —CD₂CD₂H, and —CD₂CDH₂;

an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, and a naphthyl group; and

an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, and a naphthyl group, each substituted with at least one selected from deuterium, a C₁-C₁₀ alkyl group, and a phenyl group, but embodiments are not limited thereto.

In some embodiments, in Formula 1, R₁₁ to R₁₈ may each independently be selected from hydrogen, deuterium, —F, a cyano group, a nitro group, —SF₅, a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, an n-hexyl group, an iso-hexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an iso-heptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an iso-octyl group, a sec-octyl group, a tert-octyl group, an n-nonyl group, an iso-nonyl group, a sec-nonyl group, a tert-nonyl group, an n-decyl group, an iso-decyl group, a sec-decyl group, a tert-decyl group, a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a bicyclo[2.2.1]heptanyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, a fluorenyl group, a carbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, and a dibenzosilolyl group;

a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, an n-hexyl group, an iso-hexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an iso-heptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an iso-octyl group, a sec-octyl group, a tert-octyl group, an n-nonyl group, an iso-nonyl group, a sec-nonyl group, a tert-nonyl group, an n-decyl group, an iso-decyl group, a sec-decyl group, a tert-decyl group, a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a bicyclo[2.2.1]heptanyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, a fluorenyl group, a carbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, and a dibenzosilolyl group, each substituted with at least one selected from deuterium, —F, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a cyano group, a nitro group, a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a cyclopentyl group, a cyclopentyl group substituted with deuterium, a cyclohexyl group, a cyclohexyl group substituted with deuterium, a cycloheptyl group, a cycloheptyl group substituted with deuterium, a cyclooctyl group, a cyclooctyl group substituted with deuterium, a bicyclo[2.2.1]heptanyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, a fluorenyl group, a carbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, and —Si(Q₃₃)(Q₃₄)(Q₃₅), and

—N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), and —P(═O)(Q₈)(Q₉),

wherein Q₁ to Q₉ and Q₃₃ to Q₃₅ may each independently be selected from

—CH₃, —CD₃, —CD₂H, —CDH₂, —CH₂CH₃, —CH₂CD₃, —CH₂CD₂H, —CH₂CDH₂, —CHDCH₃, —CHDCD₂H, —CHDCDH₂, —CHDCD₃, —CD₂CD₃, —CD₂CD₂H, and —CD₂CDH₂;

an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, and a naphthyl group; and

an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, and a naphthyl group, each substituted with at least one selected from deuterium, a C₁-C₁₀ alkyl group, and a phenyl group,

but embodiments are not limited thereto.

In some embodiments, in Formula 1, R₁₁ to R₁₈ may each independently be selected from hydrogen, deuterium, —F, a cyano group, a nitro group, —SF₅, —CH₃, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, groups represented by Formulae 9-1 to 9-21, groups represented by Formulae 10-1 to 10-246, —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), and —P(═O)(Q₈)(Q₉), but embodiments are not limited thereto:

wherein, Q₁ to Q₉ may each independently be selected from

—CH₃, —CD₃, —CD₂H, —CDH₂, —CH₂CH₃, —CH₂CD₃, —CH₂CD₂H, —CH₂CDH₂, —CHDCH₃, —CHDCD₂H, —CHDCDH₂, —CHDCD₃, —CD₂CD₃, —CD₂CD₂H, and —CD₂CDH₂;

an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, and a naphthyl group; and

an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, and a naphthyl group, each substituted with at least one selected from deuterium, a C₁-C₁₀ alkyl group, and a phenyl group,

in Formulae 9-1 to 9-21 and 10-1 to 10-246,

* indicates a binding site to an adjacent atom,

the term “i-Pr” represents an iso-propyl group, the term “i-Bu” represents an iso-butyl group, the term “t-Bu” represents a t-butyl group,

the term “Ph” represents a phenyl group,

the term “1-Nph” represents a 1-naphthyl group, the term “2-Nph” represents a 2-naphthyl group,

the term “2-Pyr” represents a 2-pyridyl group, the term “3-Pyr” represents a 3-pyridyl group, the term “4-Pyr” represents a 4-pyridyl group, and

the term “TMS” represents a trimethylsilyl group.

In Formula 1, b11 to b14 may respectively indicate numbers of R₁₁ to R₁₄, which may each independently be selected from 1, 2, 3, 4, and 5. When b11 is 2 or greater, at least two groups R₁₁ may be identical to or different from each other, and b12 to b14 may be substantially the same as b11.

In some embodiments, in Formula 1, b11 to b14 may each independently be selected from 1 and 2, but embodiments are not limited thereto.

In Formula 1, n11 to n14 may respectively indicate numbers of *-[(L₁₄)_(a14)-(R₁₁)_(b11)], *-[(L₁₅)_(a15)-(R₁₂)_(b12)], *-[(L₁₆)_(a16)-(R₁₃)_(b13)], and *-[(L₁₇)_(a17)-(R₁₄)_(b14)], which may each independently be selected from 0, 1, 2, 3, 4, and 5. When n11 is 2 or greater, at least two groups *-[(L₁₄)_(a14)-(R₁₁)_(b11)] may be identical to or different from each other. When n12 is 2 or greater, at least two groups *-[(L₁₅)_(a15)-(R₁₂)_(b12)] may be identical to or different from each other. When n13 is 2 or greater, at least two groups *-[(L₁₆)_(a16)-(R₁₃)_(b13)] may be identical to or different from each other. When n14 is 2 or greater, at least two groups *-[(L₁₇)_(a17)-(R₁₄)_(b14)] may be identical to or different from each other.

In Formula 1, two adjacent groups R₁₁ of a plurality of groups R₁₁ may optionally be bound to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group,

two adjacent groups R₁₂ of a plurality of groups R₁₂ may optionally be bound to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group,

two adjacent groups R₁₃ of a plurality of groups R₁₃ may optionally be bound to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group,

two adjacent groups R₁₄ of a plurality of groups R₁₄ may optionally be bound to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group, and

at least two of R₁₁ to R₁₄, wherein the at least two of R₁₁ to R₁₄ are adjacent to each other, may optionally be bound to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group.

In some embodiments, in Formula 1, a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group formed by an optional bond between the two adjacent groups R₁₁ of a plurality of groups R₁₁, the two adjacent groups R₁₂ of a plurality of groups R₁₂, the two adjacent groups R₁₃ of a plurality of groups R₁₃, the two adjacent groups R₁₄ of a plurality of groups R₁₄, and the at least two of R₁₁ to R₁₄ may be selected from:

a pentadiene group, a cyclohexane group, a cycloheptane group, an adamantane group, a bicycle-heptane group, a bicyclo-octane group, a benzene group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a naphthalene group, an anthracene group, a tetracene group, a phenanthrene group, a dihydronaphthalene group, a phenalene group, a benzothiophene group, a benzofuran group, an indene group, an indole group, a benzosilole group, a thienopyridine group, a furopyridine group, a cyclopentapyridine group, a pyrrolopyridine group, and a silolopyridine group;

a pentadiene group, a cyclohexane group, a cycloheptane group, an adamantane group, a bicycle-heptane group, a bicyclo-octane group, a benzene group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a naphthalene group, an anthracene group, a tetracene group, a phenanthrene group, a dihydronaphthalene group, a phenalene group, a benzothiophene group, a benzofuran group, an indene group, an indole group, a benzosilole group, a thienopyridine group, a furopyridine group, a cyclopentapyridine group, a pyrrolopyridine group, and a silolopyridine group, each substituted with at least one R_(1a), but embodiments are not limited thereto.

R_(1a) may be substantially the same as R₁ described herein.

As used herein, * and *’ each indicate a binding site to an adjacent atom.

In an embodiment, in Formula 1, a moiety represented by

may be selected from groups represented by Formulae 2-1 to 2-16:

wherein, in Formulae 2-1 to 2-16,

X₂₁ may be N or C-[(L₂₁)_(a21)-(R₂₁)_(b21)], X₂₂ may be N or C-[(L₂₂)_(a22)-(R₂₂)_(b22)], X₂₃ may be N or C-[(L₂₃)_(a23)-(R₂₃)_(b23)], X₂₄ may be N or C-[(L₂₄)_(a24)-(R₂₄)_(b24)], X₂₅ may be N or C-[(L₂₅)_(a25)-(R₂₅)_(b25)], X₂₆ may be N or C-[(L₂₆)_(a26)-(R₂₆)_(b26)], X₂₇ may be N or C-[(L₂₇)_(a27)-(R₂₇)_(b27)], X₂₈ may be N or C-[(L₂₈)_(a28)-(R₂₈)_(b28)],

X₂₉ may be selected from C(R_(29a))(R_(29a))(R_(29b)), N-[(L₂₉)_(a29)-(R_(29a))_(b29a)], O, S, and Si(R_(29a))(R_(29b)),

L₂₁ to L₂₉ may each independently be substantially the same as described herein with reference to L₁₄,

a21 to a29 may each independently be substantially the same as described herein with reference to a14,

R₂₁ to R₂₈ and R_(29a) to R_(2gh) may each independently be substantially the same as described herein with reference to R₁₁,

b21 to b29 and b29a may each independently be substantially the same as described herein with reference to b11, and

* and *′ may each indicate a binding site to an adjacent atom.

In some embodiments, in Formulae 2-1 to 2-16, X₂₁ may be C-[(L₂₁)_(a21)-(R₂₁)_(b21)], X₂₂ may be C-[(L₂₂)_(a22)-(R₂₂)_(b22)], X₂₃ may be C-[(L₂₃)_(a23)-(R₂₃)_(b23)], X₂₄ may be C-[(L₂₄)_(a24)-(R₂₄)_(b24)], X₂₅ may be C-[(L₂₅)_(a25)-(R₂₅)_(b25)], X₂₆ may be C-[(L₂₆)_(a26)-(R₂₆)_(b26)], X₂₇ may be C-[(L₂₇)_(a27)-(R₂₇)_(b27)], and X₂₈ may be C-[(L₂₈)_(a28)-(R₂₈)_(b28)], but embodiments are not limited thereto.

In one or more embodiments, in Formula 1, a moiety represented by

may be a group represented by Formula 3-1:

wherein, in Formula 3-1,

Y₁₁ may be the same as described herein,

X₃₁ may be N or C-[(L₃₁)_(a31)-(R₃₁)_(31b)], X₃₂ may be N or C-[(L₃₂)_(a32)-(R₃₂)_(b32)], X₃₃ may be N or C-[(L₃₃)_(a33)-(R₃₃)_(b33)],

L₃₁ to L₃₃ may each independently be substantially the same as described herein with reference to L₁₅,

a31 to a33 may each independently be substantially the same as described herein with reference to a15,

R₃₁ to R₃₃ may each independently be substantially the same as described herein with reference to R₁₂,

b31 to b33 may each independently be substantially the same as described herein with reference to b12, and

*, *′, and *″ may each indicate a binding site to an adjacent atom.

In some embodiments, in Formula 3-1, X₃₁ may be C-[(L₃₁)_(a31)-(R₃₁)_(b31)], X32 may be C-[(L₃₂)_(a32)-(R₃₂)_(b32)], and X₃₃ may be C-[(L₃₃)_(a33)-(R₃₃)_(b33)], but embodiments are not limited thereto.

In an embodiment, in Formula 1, a moiety represented by

may be selected from groups represented by Formulae 4-1 to 4-22:

wherein, in Formulae 4-1 to 4-22,

X₄₁ may be N or C-[(L₄₁)_(a41)-(R₄₁)_(b41)], X₄₂ may be N or C-[(L₄₂)_(a42)-(R₄₂)_(b42)], X₄₃ may be N or C-[(L₄₃)_(a43)-(R₄₃)_(b43)], X₄₄ may be N or C-[(L₄₄)_(a44)-(R₄₄)_(b44)], X₄₅ may be N or C-[(L₄₅)_(a45)-(R₄₅)_(b45)], X₄₆ may be N or C-[(L₄₆)_(a46)-(R₄₆)_(b46)], X₄₇ may be N or C-[(L₄₇)_(a47)-(R₄₇)_(b47)],

X₄₉ may be C(R_(49a))(R_(49b)), N-[(L₄₉)_(a49)-(R_(49a))_(b49a)], O, S, or Si(R_(49a))(R_(49b)),

L₄₁ to L₄₇ and L₄₉ may each independently be substantially the same as described herein with reference to L₁₅,

a41 to a47 and a49 may each independently be substantially the same as described herein with reference to a15,

R₄₁ to R₄₇ and R_(49a) to R_(49h) may each independently be substantially the same as described herein with reference to R₁₃,

b41 to b47 and b49a may each independently be substantially the same as described herein with reference to b13, and

*, *′, and *″ may each indicate a binding site to an adjacent atom.

In some embodiments, in Formulae 4-1 to 4-22, X₄₁ may be C-[(L₄₁)_(a41)-(R₄₁)_(b41)], X₄₂ may be C-[(L₄₂)_(a42)-(R₄₂)_(b42)], X₄₃ may be C-[(L₄₃)_(a43)-(R₄₃)_(b43)], X₄₄ may be C-[(L₄₄)_(a44)-(R₄₄)_(b44)], X₄₅ may be C-[(L₄₅)_(a45)-(R₄₅)_(b45)], X₄₆ may be C-[(L₄₆)_(a46)-(R₄₆)_(b46)], and X₄₇ may be C-[(L₄₇)_(a47)-(R₄₇)_(b47)], but embodiments are not limited thereto.

In one or more embodiments, in Formula 1, a moiety represented by

may be selected from groups represented by Formulae 5-1 to 5-32:

wherein, in Formulae 5-1 to 5-32,

X₅₁ may be N or C-[(L₅₁)_(a51)-(R₅₁)_(b51)], X₅₂ may be N or C-[(L₅₂)_(a52)-(R₅₂)_(b52)], X₅₃ may be N or C-[(L₅₃)_(a53)-(R₅₃)_(b53)], X₅₄ may be N or C-[(L₅₄)_(a54)-(R₅₄)_(b54)], X₅₅ may be N or C-[(L₅₅)_(a55)-(R₅₅)_(b55)], X₅₆ may be N or C-[(L₅₆)_(a56)-(R₅₆)_(b56)], X₅₇ may be N or C-[(L₅₇)_(a57)-(R₅₇)_(b57)], X₅₈ may be N or C-[(L₅₈)_(a58)-(R₅₈)_(b58)], X₅₉ may be C(R_(59a))(R_(59b)), N-[(L₅₉)_(a59)-(R_(59a))_(b59a)], O, S, or Si(R_(59a))(R_(59b)),

L₅₁ to L₅₉ may each independently be substantially the same as described herein with reference to L₁₇,

a51 to a59 may each independently be substantially the same as described herein with reference to a17,

R₅₁ to R₅₈ and R_(59a) to R_(59h) may each independently be substantially the same as described herein with reference to R₁₄,

b51 to b58 and b59a may each independently be substantially the same as described herein with reference to b14, and

* and *′ may each indicate a binding site to an adjacent atom.

In some embodiments, in Formulae 5-1 to 5-8, X₅₁ may be C-[(L₅₁)_(a51)-(R₅₁)_(b51)], X₅₂ may be C-[(L₅₂)_(a52)-(R₅₂)_(b52), X₅₃ may be C-[(L₅₃)_(a53)-(R₅₃)_(b53)], X₅₄ may be C-[(L₅₄)_(a54)-(R₅₄)_(b54)], X₅₅ may be C-[(L₅₅)_(a55)-(R₅₅)_(b55)], X₅₆ may be C-[(L₅₆)_(a56)-(R₅₆)_(b56)], X₅₇ may be C-[(L₅₇)_(a57)-(R₅₇)_(b57)], and X₅₈ may be C-[(L₅₈)_(a58)(R₅₈)_(b58)], but embodiments are not limited thereto.

In some embodiments, in Formula 1,

a moiety represented by may be selected

may be selected from groups represented by Formulae 2-1 and 2-5 to 2-10,

a moiety represented by

may by selected from groups represented by Formula 3-1,

a moiety represented by

may be selected from groups represented by Formulae 4-1 and 4-4 to 4-11, and

a moiety represented by

may by selected from groups represented by Formula 5-1, but embodiments are not limited thereto.

In an embodiment, the organometallic compound may be represented by any one of Formulae 1-1 to 1-4:

wherein, in Formulae 1-1 to 1-4,

M₁₁, T₁₁, Y₁₁, L₁₁ to L₁₇, a11 to a17, R₁₁ to R₁₄, b11 to b14, and n11 to n14 may be the same as those described herein with reference to Formula 1.

In some embodiments, the organometallic compound may be selected from Compounds 1 to 89, but embodiments are not limited thereto:

wherein in Compounds 1 to 89,

the term “TMS” represents a trimethylsilyl group.

The organometallic compound represented by Formula 1 may include a 5-membered ring represented by A₁₅, and A₁₅ and A₁₂ may share a nitrogen atom. Accordingly, in the organometallic compound represented by Formula 1, the highest occupied molecular orbital (HOMO) may be easily separated from the lowest unoccupied molecular orbital (LUMO), which may facilitate charge transfer. Thus, the organometallic compound represented by Formula 1 is advantageous in terms of its emission properties, and therefore, an organic light-emitting device employing the organometallic compound may have high efficiency.

Furthermore, the organometallic compound represented by Formula 1 includes N shared by the 5-membered ring and a 6-membered ring, and thus, an emission wavelength of the organometallic compound may be longer to enable the compound to emit red light.

In addition, in Formula 1, a cyclometalated ring formed of A₁₅, A₁₂, A₁₃, and M₁₁ may be a 6-membered ring, a 7-membered ring, or an 8-membered ring. Accordingly, a full width at half maximum (FWHM) of the organometallic compound represented by Formula 1 may decrease, and thus, efficiency of an organic light-emitting device including the organometallic compound may improve.

For example, the HOMO, LUMO, singlet (S₁), and triplet (T₁) energy levels of the organometallic Compounds 4, 5, 7, 18, 24, 52, 63 to 68, 77, and 78 were evaluated by using a Gaussian according to a density functional theory (DFT) method (structure optimization was performed at a degree of B3LYP, and 6-31G(d,p)). The results thereof are shown in Table 1.

TABLE 1 S₁ energy T₁ energy HOMO LUMO level level Compound No. (eV) (eV) (eV) (eV) 4 −4.560 −1.675 2.384 2.147 5 −4.545 −1.710 2.338 2.080 7 −4.496 −1.665 2.339 2.085 18 −4.385 −1.717 2.192 2.022 24 −4.396 −1.820 2.101 2.008 52 −4.527 −2.295 1.779 1.711 63 −4.453 −1.866 2.123 1.984 64 −4.435 −2.085 1.879 1.809 65 −4.450 −1.768 2.202 1.980 68 −4.393 −1.989 1.956 1.829 77 −4.654 −1.816 2.366 2.107 78 −4.529 −1.764 2.301 2.067

Referring to the results of Table 1, the organometallic compound of Formula 1 was found to have suitable electrical characteristics for use as a dopant in an electronic device, e.g., an organic light-emitting device.

A method of synthesizing the organometallic compound represented by Formula 1 may be apparent to one of ordinary skill in the art by referring to Synthesis Examples provided herein.

The organometallic compound represented by Formula 1 may be suitable for use in an organic layer of an organic light-emitting device, e.g., as a dopant in an emission layer of the organic layer. Thus, according to another aspect, there is provided an organic light-emitting device that may include:

a first electrode;

a second electrode; and

an organic layer disposed between the first electrode and the second electrode,

wherein the organic layer includes an emission layer,

and wherein the organic layer includes at least one organometallic compound represented by Formula 1.

Since the organic light-emitting device has an organic layer including the organometallic compound represented by Formula 1, the organic light-emitting device may have a low driving voltage, high efficiency, high power, high quantum efficiency, a long lifespan, low roll-off, and excellent color purity.

The organometallic compound represented by Formula 1 may be used in a pair of electrodes of an organic light-emitting device. For example, the organometallic compound represented by Formula 1 may be included in the emission layer. In this case, the organometallic compound may serve as a dopant and the emission layer may further include a host (that is, an amount of the organometallic compound represented by Formula 1 may be smaller than that of the host).

As used herein, “(for example, the organic layer) including at least one organometallic compound” means that “(the organic layer) including an organometallic compound of Formula 1, or at least two different organometallic compounds of Formula 1”.

For example, the organic layer may include Compound 1 only as the organometallic compound. In this embodiment, Compound 1 may be included in the emission layer of the organic light-emitting device. In some embodiments, the organic layer may include Compounds 1 and 2 as the organometallic compounds. In this embodiment, Compounds 1 and 2 may be included in the same layer (for example, Compounds 1 and 2 may be both included in the emission layer).

The first electrode may be an anode, which is a hole injection electrode, and the second electrode may be a cathode, which is an electron injection electrode. In some embodiments, the first electrode may be a cathode, which is an electron injection electrode, and the second electrode may be an anode, which is a hole injection electrode.

For example, in the organic light-emitting device, the first electrode may be an anode, the second electrode may be a cathode, and the organic layer may further include a hole transport region disposed between the first electrode and the emission layer and an electron transport region disposed between the emission layer and the second electrode, wherein the hole transport region may include a hole injection layer, a hole transport layer, an electron blocking layer, or a combination thereof, and wherein the electron transport region may include a hole blocking layer, an electron transport layer, an electron injection layer, or a combination thereof.

As used herein, the term “organic layer” refers to a single and/or a plurality of layers disposed between the first electrode and the second electrode in an organic light-emitting device. The “organic layer” may include not only organic compounds but also organometallic complexes including metals.

FIG. 1 illustrates a schematic view of an organic light-emitting device 10 according to an embodiment. Hereinafter a structure and a method of manufacturing an organic light-emitting device according to an embodiment will be described with reference to FIG. 1. The organic light-emitting device 10 may include a first electrode 11, an organic layer 15, and a second electrode 19, which may be sequentially layered in the stated order.

A substrate may be additionally disposed under the first electrode 11 or on the second electrode 19. The substrate may be a conventional substrate used in organic light-emitting devices, e.g., a glass substrate or a transparent plastic substrate, each having excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and water repellency.

The first electrode 11 may be formed by vacuum-depositing or sputtering a material for forming the first electrode 11 on the substrate. The first electrode 11 may be an anode. The material for forming the first electrode 11 may be selected from materials having a high work function for easy hole injection. The first electrode 11 may be a reflective electrode, a semi-transmissive electrode, or a transmissive electrode. The material for forming the first electrode 11 may be selected from indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO₂), and zinc oxide (ZnO). In some embodiments, the material for forming the first electrode 11 may be a metal, such as magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), or magnesium-silver (Mg—Ag).

The first electrode 11 may have a single-layered structure or a multi-layered structure including a plurality of layers. In some embodiments, the first electrode 11 may have a triple-layered structure of ITO/Ag/ITO, but embodiments are not limited thereto.

The organic layer 15 may be disposed on the first electrode 11.

The organic layer 15 may include a hole transport region, an emission layer, and an electron transport region.

The hole transport region may be disposed between the first electrode 11 and the emission layer.

The hole transport region may include a hole injection layer, a hole transport layer, an electron blocking layer, a buffer layer, or a combination thereof.

The hole transport region may include a hole injection layer only or a hole transport layer only. In some embodiments, the hole transport region may include a hole injection layer and a hole transport layer, which are sequentially stacked on the first electrode 11. In some embodiments, the hole transport region may include a hole injection layer, a hole transport layer, and an electron blocking layer, which are sequentially stacked on the first electrode 11.

When the hole transport region includes a hole injection layer, the hole injection layer may be formed on the first electrode 11 by using one or more suitable methods, such as vacuum deposition, spin coating, casting, and Langmuir-Blodgett (LB) deposition.

When a hole injection layer is formed by vacuum deposition, for example, the vacuum deposition may be performed at a temperature in a range of about 100° C. to about 500° C., at a vacuum degree in a range of about 10⁻⁸ torr to about 10⁻³ torr, and at a rate in a range of about 0.01 Angstroms per second (Å/sec) to about 100 Å/sec, though the conditions may vary depending on a compound used as a hole injection material and a structure and thermal properties of a desired hole injection layer, but embodiments are not limited thereto.

When a hole injection layer is formed by spin coating, the spin coating may be performed at a rate in a range of about 2,000 revolutions per minute (rpm) to about 5,000 rpm and at a temperature in a range of about 80° C. to 200° C. to facilitate removal of a solvent after the spin coating, though the conditions may vary depending on a compound used as a hole injection material and a structure and thermal properties of a desired hole injection layer, but embodiments are not limited thereto.

The conditions for forming a hole transport layer and an electron blocking layer may be inferred from the conditions for forming the hole injection layer.

The hole transport region may include at least one selected from m-MTDATA, TDATA, 2-TNATA, NPB, β-NPB, TPD, spiro-TPD, spiro-NPB, methylated-NPB, TAPC, HMTPD, 4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA), polyaniline/dodecylbenzene sulfonic acid (PANI/DBSA), poly(3,4-ethylenedioxythiophene)/poly(4-styrene sulfonate) (PEDOT/PSS), polyaniline/camphor-sulfonic acid (PANT/CSA), (polyaniline)/poly(4-styrene sulfonate) (PANI/PSS), a compound represented by Formula 201, and a compound represented by Formula 202:

wherein, in Formula 201, Ar₁₀₁ and Ar₁₀₂ may each independently be selected from

a phenylene group, a pentalenylene group, an indenylene group, a naphthylene group, an azulenylene group, a heptalenylene group, an acenaphthylene group, a fluorenylene group, a phenalenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylenylene group, a naphthacenylene group, a picenylene group, a perylenylene group, and a pentacenylene group; and

a phenylene group, a pentalenylene group, an indenylene group, a naphthylene group, an azulenylene group, a heptalenylene group, an acenaphthylene group, a fluorenylene group, a phenalenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylenylene group, a naphthacenylene group, a picenylene group, a perylenylene group, and a pentacenylene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group.

In Formula 201, xa and xb may each independently be an integer from 0 to 5. In some embodiments, xa and xb may each independently be an integer of 0, 1, or 2. In some embodiments, xa may be 1, and xb may be 0, but embodiments are not limited thereto.

In Formulae 201 and 202, R₁₀₁ to R₁₀₈, R₁₁₁ to R₁₁₉, and R₁₂₁ to R₁₂₄ may each independently be selected from

hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₁₀ alkyl group (e.g., a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, or a hexyl group), and a C₁-C₁₀ alkoxy group (e.g., a methoxy group, an ethoxy group, a propoxy group, a butoxy group, or a pentoxy group);

a C₁-C₁₀ alkyl group and a C₁-C₁₀ alkoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, and a phosphoric acid group or a salt thereof;

a phenyl group, a naphthyl group, an anthracenyl group, a fluorenyl group, and a pyrenyl group; and

a phenyl group, a naphthyl group, an anthracenyl group, a fluorenyl group, and a pyrenyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₁₀ alkyl group, and a C₁-C₁₀ alkoxy group, but embodiments are not limited thereto.

In Formula 201, R₁₀₉ may be selected from

a phenyl group, a naphthyl group, an anthracenyl group, and a pyridinyl group; and

a phenyl group, a naphthyl group, an anthracenyl group, and a pyridinyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthyl group, an anthracenyl group, and a pyridinyl group.

In some embodiments, the compound represented by Formula 201 may be represented by Formula 201A, but embodiments are not limited thereto:

wherein, in Formula 201A, R₁₀₁, R₁₁₁, R₁₁₂, and R₁₀₉ may be the same as those described herein.

In some embodiments, the compounds represented by Formulae 201 and 202 may include Compounds HT1 to HT20, but embodiments are not limited thereto:

The thickness of the hole transport region may be in a range of about 100 Angstroms (Å) to about 10,000 Å, for example, about 100 Å to about 1,000 Å. When the hole transport region includes at least one selected from a hole injection layer and a hole transport layer, the thickness of the hole injection layer may be in a range of about 100 Å to about 10,000 Å, for example, about 100 Å to about 1,000 Å, and the thickness of the hole transport layer may be in a range of about 50 Å to about 2,000 Å, for example, about 100 Å to about 1,500 Å. While not wishing to be bound by theory, it is understood that when the thicknesses of the hole transport region, the hole injection layer, and the hole transport layer are within any of these ranges, excellent hole transporting characteristics may be obtained without a substantial increase in driving voltage.

The hole transport region may include a charge generating material as well as the aforementioned materials, to improve conductive properties of the hole transport region. The charge generating material may be substantially homogeneously or non-homogeneously dispersed in the hole transport region.

The charge generating material may include, for example, a p-dopant. The p-dopant may be selected from a quinone derivative, a metal oxide, and a cyano group-containing compound, but embodiments are not limited thereto. For example, non-limiting examples of the p-dopant include a quinone derivative, such as tetracyanoquinodimethane (TCNQ) or 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinonedimethane (F4-TCNQ); a metal oxide, such as a tungsten oxide or a molybdenum oxide; and a compound containing a cyano group, such as Compound HT-D1, but embodiments are not limited thereto:

The hole transport region may further include a buffer layer.

The buffer layer may compensate for an optical resonance distance depending on a wavelength of light emitted from the emission layer to improve efficiency of an organic light-emitting device.

An emission layer may be formed on the hole transport region by using one or more suitable methods, such as vacuum deposition, spin coating, casting, or LB deposition. When the emission layer is formed by vacuum deposition or spin coating, vacuum deposition and coating conditions for the emission layer may be generally similar to the conditions for forming a hole injection layer, though the conditions may vary depending on the compound used.

When the hole transport region includes an electron blocking layer, a material for forming the electron blocking layer may be selected from the materials for forming a hole transport region and host materials described herein, but embodiments are not limited thereto. In some embodiments, when the hole transport region includes an electron blocking layer, mCP described herein may be used for forming the electron blocking layer.

The emission layer may include a host and a dopant, and the dopant may include the organometallic compound represented by Formula 1.

The host may include at least one selected from TPBi, TBADN, ADN (also known as “DNA”), CBP, CDBP, TCP, mCP, Compound H50, and Compound H51:

In some embodiments, the host may further include a compound represented by Formula 301:

wherein, in Formula 301, AR₁₁₁ and Ar₁₁₂ may each independently be selected from

a phenylene group, a naphthylene group, a phenanthrenylene group, and a pyrenylene group; and

a phenyl group, a phenylene group substituted with at least one selected from a naphthyl group and an anthracenyl group, a naphthylene group, a phenanthrenylene group, and a pyrenylene group.

In Formula 301, Ar₁₁₃ to Ar₁₁₆ may each independently be selected from

a C₁-C₁₀ alkyl group, a phenyl group, a naphthyl group, a phenanthrenyl group, and a pyrenyl group; and

a phenyl group, a phenyl group substituted with at least one selected from a naphthyl group and an anthracenyl group, a naphthyl group, a phenanthrenyl group, and a pyrenyl group.

In Formula 301, g, h, i, and j may each independently be an integer from 0 to 4. For example, g, h, i, and j may each independently be 0, 1, or 2.

In Formula 301, Ar₁₁₃ and Ar₁₁₆ may each independently be selected from

a C₁-C₁₀ alkyl group substituted with at least one selected from a phenyl group, a naphthyl group, and an anthracenyl group;

a phenyl group, a naphthyl group, an anthracenyl group, a pyrenyl group, a phenanthrenyl group, and a fluorenyl group; and

a phenyl group, a naphthyl group, an anthracenyl group, a pyrenyl group, a phenanthrenyl group, and a fluorenyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a phenyl group, a naphthyl group, an anthracenyl group, a pyrenyl group, a phenanthrenyl group, a fluorenyl group, and

but embodiments are not limited thereto.

In some embodiments, the host may include a compound represented by Formula 302:

In Formula 302, Ar₁₂₂ to Ar₁₂₅ may each independently be substantially the same as Ar₁₁₃ described with reference to Formula 301.

In Formula 302, Ar₁₂₆ and Ar₁₂₇ may each independently be a C₁-C₁₀ alkyl group (e.g., a methyl group, an ethyl group, or a propyl group).

In Formula 302, k and l may each independently be an integer from 0 to 4. In some embodiments, k and l may each be 0, 1, or 2.

In some embodiments, the compounds represented by Formulae 301 and 302 may each include at least one of Compounds H1 to H42, but embodiments are not limited thereto:

When the organic light-emitting device 10 is a full-color organic light-emitting device, the emission layer may be patterned into a red emission layer, a green emission layer, and a blue emission layer. In some embodiments, the emission layer may have a structure in which the red emission layer, the green emission layer, and/or the blue emission layer are layered so as to emit white light. In some embodiments, the structure of the emission layer may vary.

When the emission layer includes the host and the dopant, an amount of the dopant may be selected from a range of about 0.01 parts to about 15 parts by weight based on about 100 parts by weight of the host, but embodiments are not limited thereto.

The thickness of the emission layer may be in a range of about 100 Å to about 1,000 Å, and in some embodiments, about 200 Å to about 600 Å. While not wishing to be bound by theory, it is understood that when the thickness of the emission layer is within any of these ranges, improved luminous characteristics may be obtained without a substantial increase in driving voltage.

Next, an electron transport region may be formed on the emission layer.

The electron transport region may include a hole blocking layer, an electron transport layer, an electron injection layer, or a combination thereof.

In some embodiments, the electron transport region may have a hole blocking layer/electron transport layer/electron injection layer structure or an electron transport layer/electron injection layer structure, but embodiments are not limited thereto. The electron transport layer may have a single-layered structure or a multi-layered structure including two or more different materials.

The conditions for forming a hole blocking layer, an electron transport layer, and an electron injection layer may be inferred from the conditions for forming the hole injection layer.

When the electron transport region includes a hole blocking layer, the hole blocking layer may include, for example, at least one selected from BCP, Bphen, and BAlq, but embodiments are not limited thereto:

The thickness of the hole blocking layer may be in a range of about 20 Å to about 1,000 Å, for example, about 30 Å to about 300 Å. While not wishing to be bound by theory, it is understood that when the thickness of the hole blocking layer is within these ranges, excellent hole blocking characteristics may be obtained without a substantial increase in driving voltage.

The electron transport layer may further include at least one selected from BCP, Bphen, Alq₃, BAlq, TAZ, and NTAZ:

In some embodiments, the electron transport layer may include at least one selected from Compounds ET1 and ET2, but embodiments are not limited thereto:

The thickness of the electron transport layer may be in a range of about 100 Å to about 1,000 Å, and in some embodiments, about 150 Å to about 500 ÅA. While not wishing to be bound by theory, it is understood that when the thickness of the electron transport layer is within any of these ranges, excellent electron transport characteristics may be obtained without a substantial increase in driving voltage.

The electron transport layer may further include a material including metal, in addition to the materials described above.

The material including metal may include a lithium (Li) complex. The Li complex may include, e.g., Compound ET-D1 (lithium quinolate, LiQ) or Compound ET-D2:

The electron transport region may include an electron injection layer that facilitates electron injection from the second electrode 19.

The electron injection layer may include at least one selected from, LiF, NaCl, CsF, Li₂O, and BaO.

The thickness of the electron injection layer may be in a range of about 1 Å to about 100 Å, and in some embodiments, about 3 Å to about 90 Å. While not wishing to be bound by theory, it is understood that when the thickness of the electron injection layer is within any of these ranges, excellent electron injection characteristics may be obtained without a substantial increase in driving voltage.

The second electrode 19 may be formed on the organic layer 15. The second electrode 19 may be a cathode. A material for forming the second electrode 19 may be a material with a relatively low work function, such as a metal, an alloy, an electrically conductive compound, or a mixture thereof. Examples of the material for forming the second electrode 19 may include lithium (Li), magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), and magnesium-silver (Mg—Ag). In some embodiments, ITO or IZO may be used to form a transmissive second electrode 19 to manufacture a top-emission light-emitting device. In some embodiments, the material for forming the second electrode 19 may vary.

Hereinbefore the organic light-emitting device 10 has been described with reference to FIG. 1, but embodiments are not limited thereto.

According to an aspect of another embodiment, there is provided a diagnostic composition that includes at least one organometallic compound represented by Formula 1.

Since the organometallic compound represented by Formula 1 may provide high emission efficiency, the diagnostic efficiency of the diagnostic composition that includes the organometallic compound represented by Formula 1 may be excellent.

The diagnostic composition may be applied in various ways, such as in a diagnostic kit, a diagnostic reagent, a biosensor, or a biomarker.

The terms “a thienopyridine group, a furopyridine group, a cyclopentapyridine group, a pyrrolopyridine group, a silolopyridine group, a benzothienopyridine group, a benzofuropyridine group, an indenopyridine group, an indolopyridine group, and a benzosilolopyridine group”, as used herein, may each have the same backbone as “a benzothiophene group, a benzofuran group, an indene group, an indole group, a benzosilole group, a dibenzothiophene group, a dibenzofuran group, a fluorene group, a carbazole group, and a dibenzosilole group”, respectively, each having a heterocyclic ring in which a ring-forming carbon atom is substituted with nitrogen atom.

The terms “a thienopyrimidine group, a furopyrimidine group, a cyclopentapyrimidine group, a pyrrolopyrimidine group, a silolopyrimidine group, a benzothienopyrimidine group, a benzofuropyrimidine group, an indenopyrimidine group, an indolopyrimidine group, and a benzosilolopyrimidine group”, as used herein, may each have the same backbone as “a benzothiophene group, a benzofuran group, an indene group, an indole group, a benzosilole group, a dibenzothiophene group, a dibenzofuran group, a fluorene group, a carbazole group, and a dibenzosilole group”, respectively, each having a heterocyclic ring in which two ring-forming carbon atoms are substituted with nitrogen atoms.

The term “C₁-C₆₀ alkyl group” as used herein refers to a linear or branched saturated aliphatic hydrocarbon monovalent group having 1 to 60 carbon atoms. Examples thereof include a methyl group, an ethyl group, a propyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an iso-amyl group, and a hexyl group. The term “C₁-C₆₀ alkylene group” as used herein refers to a divalent group having the same structure as the C₁-C₆₀ alkyl group.

The term “C₁-C₆₀ alkoxy group” as used herein refers to a monovalent group represented by -0A₁₀₁ (wherein A₁₀₁ is a C₁-C₆₀ alkyl group). Examples thereof include a methoxy group, an ethoxy group, and an iso-propyloxy (iso-propoxy) group.

The term “C₂-C₆₀ alkenyl group” as used herein refers to a group formed by placing at least one carbon-carbon double bond in the middle or at the terminus of the C₂-C₆₀ alkyl group. Examples thereof include an ethenyl group, a propenyl group, and a butenyl group. The term “C₂-C₆₀ alkenylene group” as used herein refers to a divalent group having the same structure as the C₂-C₆₀ alkenyl group.

The term “C₂-C₆₀ alkynyl group” as used herein refers to a group formed by placing at least one carbon-carbon triple bond in the middle or at the terminus of the C₂-C₆₀ alkyl group. Examples thereof include an ethenyl group and a propenyl group. The term “C₂-C₆₀ alkynylene group” as used herein refers to a divalent group having the same structure as the C₂-C₆₀ alkynyl group.

The term “C₃-C₁₀ cycloalkyl group” as used herein refers to a monovalent monocyclic saturated hydrocarbon group including 3 to 10 carbon atoms. Examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group. The term “C₃-C₁₀ cycloalkylene group” as used herein refers to a divalent group having the same structure as the C₃-C₁₀ cycloalkyl group.

The term “C₁-C₁₀ heterocycloalkyl group” as used herein refers to a monovalent monocyclic group including at least one heteroatom selected from N, O, P, Si, and S as a ring-forming atom, and 1 to 10 carbon atoms. Examples thereof include a tetrahydrofuranyl group and a tetrahydrothiophenyl group. The term “C₁-C₁₀ heterocycloalkylene group” as used herein refers to a divalent group having the same structure as the C₁-C₁₀ heterocycloalkyl group.

The term “C₃-C₁₀ cycloalkenyl group” as used herein refers to a monovalent monocyclic group that has 3 to 10 carbon atoms and at least one carbon-carbon double bond in its ring, wherein the molecular structure as a whole is non-aromatic. Examples thereof include a cyclopentenyl group, a cyclohexenyl group, and a cycloheptenyl group. The term “C₃-C₁₀ cycloalkenylene group” as used herein refers to a divalent group having the same structure as the C₃-C₁₀ cycloalkenyl group.

The term “C₁-C₁₀ heterocycloalkenyl group” as used herein refers to a monovalent monocyclic group including at least one heteroatom selected from N, O, P, Si, and S as a ring-forming atom, 1 to 10 carbon atoms, and at least one double bond in its ring. Examples of the C₁-C₁₀ heterocycloalkenyl group include a 2,3-dihydrofuranyl group and a 2,3-dihydrothiophenyl group. The term “C₁-C₁₀ heterocycloalkylene group” as used herein refers to a divalent group having the same structure as the C₁-C₁₀ heterocycloalkyl group.

The term “C₆-C₆₀ aryl group” as used herein refers to a monovalent group having a carbocyclic aromatic system having 6 to 60 carbon atoms. The term “C₆-C₆₀ arylene group” as used herein refers to a divalent group having a carbocyclic aromatic system having 6 to 60 carbon atoms. Examples of the C₆-C₆₀ aryl group include a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a pyrenyl group, and a chrysenyl group. When the C₆-C₆₀ aryl group and the C₆-C₆₀ arylene group each include a plurality of rings, the plurality of rings may be fused to each other.

The term “C₁-C₆₀ heteroaryl group” as used herein refers to a monovalent group having a cyclic aromatic system having at least one heteroatom selected from N, O, P, Si, and S as a ring-forming atom, and 1 to 60 carbon atoms. The term “C₁-C₆₀ heteroarylene group” as used herein refers to a divalent group having a cyclic aromatic system having at least one heteroatom selected from N, O, P, Si, and S as a ring-forming atom, and 1 to 60 carbon atoms. Examples of the C₁-C₆₀ heteroaryl group include a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, and an isoquinolinyl group. When the C₁-C₆₀ heteroaryl group and the C₁-C₆₀ heteroarylene group each include a plurality of rings, the plurality of rings may be fused to each other.

The term “C₆-C₆₀ aryloxy group” as used herein indicates —OA₁₀₂ (wherein A₁₀₂ is a C₆-C₆₀ aryl group), and a C₆-C₆₀ arylthio group as used herein indicates —SA₁₀₃ (wherein A₁₀₃ is a C₆-C₆₀ aryl group).

The term “monovalent non-aromatic condensed polycyclic group” as used herein refers to a monovalent group that has two or more condensed rings and only carbon atoms (e.g., the number of carbon atoms may be in a range of 8 to 60) as ring-forming atoms, wherein the molecular structure as a whole is non-aromatic. Examples of the monovalent non-aromatic condensed polycyclic group include a fluorenyl group. The term “divalent non-aromatic condensed polycyclic group” as used herein refers to a divalent group having the same structure as the monovalent non-aromatic condensed polycyclic group.

The term “monovalent non-aromatic condensed heteropolycyclic group” as used herein refers to a monovalent group that has two or more condensed rings and a heteroatom selected from N, O, P, Si, and S, and carbon atoms (e.g., the number of carbon atoms may be in a range of 1 to 60), as ring-forming atoms, wherein the molecular structure as a whole is non-aromatic. The monovalent non-aromatic condensed heteropolycyclic group may include a carbazolyl group. The term “divalent non-aromatic condensed heteropolycyclic group” as used herein refers to a divalent group having the same structure as the monovalent non-aromatic condensed heteropolycyclic group.

The term “C₅-C₃₀ carbocyclic group” as used herein refers to a saturated or unsaturated cyclic group including 5 to 30 carbon atoms only as ring-forming atoms. The C₅-C₃₀ carbocyclic group may be a monocyclic group or a polycyclic group.

The term “C₁-C₃₀ heterocyclic group” as used herein refers to saturated or unsaturated cyclic group including 1 to 30 carbon atoms and at least one heteroatom selected from N, O, P, Si, and S as ring-forming atoms. The C₁-C₃₀ heterocyclic group may be a monocyclic group or a polycyclic group.

At least one substituent of the substituted C₅-C₃₀ carbocyclic group, substituted C₁-C₃₀ heterocyclic group, substituted C₁-C₆₀ alkyl group, substituted C₂-C₆₀ alkenyl group, substituted C₂-C₆₀ alkynyl group, substituted C₁-C₆₀ alkoxy group, substituted C₃-C₁₀ cycloalkyl group, substituted C₁-C₁₀ heterocycloalkyl group, substituted C₃-C₁₀ cycloalkenyl group, substituted C₁-C₁₀ heterocycloalkenyl group, substituted C₆-C₆₀ aryl group, substituted C₆-C₆₀ aryloxy group, substituted C₆-C₆₀ arylthio group, substituted C₁-C₆₀ heteroaryl group, substituted monovalent non-aromatic condensed polycyclic group, and substituted monovalent non-aromatic condensed heteropolycyclic group may be selected from:

deuterium, —F, —Cl, -Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —N(Q₁₁)(Q₁₂), —Si(Q₁₃)(Q₁₄)(Q₁₅), —B(Q₁₆)(Q₁₇), and —P(═O)(Q₁₈)(Q₁₉);

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group;

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —N(Q₂₁)(Q₂₂), —Si(Q₂₃)(Q₂₄)(Q₂₅), —B(Q₂₆)(Q₂₇), and —P(═O)(Q₂₈)(Q₂₉); and

—N(O₃₁)(Q₃₂), —Si(Q₃₃)(Q₃₄)(Q₃₅), —B(Q₃₆)(Q₃₇), and —P(═O)(Q₃₈)(Q₃₉),

wherein Q₁ to Q₉, Q₁₁ to Q₁₉, Q₂₁ to Q₂₉, and Q₃₁ to Q₃₉ may each independently be selected from hydrogen; deuterium; —F; —Cl; —Br; —I; a hydroxyl group; a cyano group; a nitro group; an amidino group; a hydrazine group; a hydrazone group; a carboxylic acid group or a salt thereof; a sulfonic acid group or a salt thereof; a phosphoric acid group or a salt thereof; a C₁-C₆₀ alkyl group; a C₁-C₆₀ alkyl group substituted with at least one of deuterium, a C₁-C₆₀ alkyl group, and a C₆-C₆₀ aryl group; a C₂-C₆₀ alkenyl group; a C₂-C₆₀ alkynyl group; a C₁-C₆₀ alkoxy group; a C₃-C₁₀ cycloalkyl group; a C₁-C₁₀ heterocycloalkyl group; a C₃-C₁₀ cycloalkenyl group; a C₁-C₁₀ heterocycloalkenyl group; a C₆-C₆₀ aryl group; a C₆-C₆₀ aryl group substituted with at least one of deuterium, a C₁-C₆₀ alkyl group, and a C₆-C₆₀ aryl group; a C₆-C₆₀ aryloxy group; a C₆-C₆₀ arylthio group; a C₁-C₆₀ heteroaryl group; a monovalent non-aromatic condensed polycyclic group; and a monovalent non-aromatic condensed heteropolycyclic group.

When a group containing a specified number of carbon atoms is substituted with any of the groups listed in the preceding paragraph, the number of carbon atoms in the resulting “substituted” group is defined as the sum of the carbon atoms contained in the original (unsubstituted) group and the carbon atoms (if any) contained in the substituent. For example, when the term “substituted C₁-C₃₀ alkyl” refers to a C₁-C₃₀ alkyl group substituted with C₆-C₃₀ aryl group, the total number of carbon atoms in the resulting aryl substituted alkyl group is C₇-C₆₀.

Hereinafter, a compound and an organic light-emitting device according to an embodiment will be described in detail with reference to Synthesis Examples and Examples, however, the present disclosure is not limited thereto. The wording “B was used instead of A” used in describing Synthesis Examples means that an identical molar equivalent of B was used in place of A.

EXAMPLES Synthesis Example 1 Synthesis of Compound 5

1) Synthesis of Intermediate 5-3

2 grams (g) (12.74 millimoles, mmol) of 2-bromopyridine, 5.9 g (15.29 mmol) of Compound 5-4, 4.4 g (31.86 mmol) of K₂CO₃, 1.0 g (0.89 mmol) of Pd(PPh₃)₄, 85 milliliters (mL) of THF, and 42.5 mL of H₂O were added to a reaction vessel, and the mixture was stirred under reflux at a temperature of 80° C. for 16 hours. The reaction mixture was cooled to room temperature, and the organic layer was extracted therefrom using 400 mL of water and 400 mL of ethyl acetate. The organic layer was dried over MgSO₄, and the solvent was removed therefrom by evaporation. The resulting residue was then separated and purified through silica gel chromatography to obtain 3.9 g of Intermediate 5-3 (yield: 72%). The compound thus obtained was identified by using liquid chromatography-mass spectrometry (LC-MS).

C₂₅H₂₈BrN: M⁺=421.14

2) Synthesis of Intermediate 5-2

3.9 g (9.17 mmol) of Intermediate 5-3, 3.5 g (13.75 mmol) of bis(pinacolato)diboron, 1.7 g (18.33 mmol) of potassium acetate, 0.37 g (0.46 mmol) of Pd(PPh₃)₂Cl₂, and 45 mL of toluene were added to a reaction vessel, and the mixture was stirred under reflux at a temperature of 120° C. for 8 hours. The reaction mixture was cooled to room temperature, and the organic layer was extracted therefrom using 300 mL of water and 300 mL of ethyl acetate. The organic layer was dried over MgSO₄, and the solvent was removed therefrom by evaporation. The resulting residue was then separated and purified through silica gel chromatography to obtain 3.2 g of Intermediate 5-2 (yield: 75%). The compound thus obtained was identified by using LC-MS.

C₃₁H₄₀BNO₂: M⁺=469.32

3) Synthesis of Intermediate 5-1

3.2 g (15.8 mmol) of Intermediate 5-2, 3.2 g (6.9 mmol) of Intermediate A, 1.9 g (14.32 mmol) of K₂CO₃, 0.46 g (0.4 mmol) of Pd(PPh₃)₄, 40 mL of THF, and 20 mL of H₂O were added to a reaction vessel, and the mixture was stirred under reflux at a temperature of 80° C. for 16 hours. The reaction mixture was cooled to room temperature, and the organic layer was extracted therefrom using 300 mL of water and 300 mL of ethyl acetate. The organic layer was dried over MgSO₄, and the solvent was removed therefrom by evaporation. The resulting residue was then separated and purified through silica gel chromatography to obtain 2.9 g of Intermediate 5-1 (yield: 75%). The compound thus obtained was identified by using LC-MS.

C₃₉H₃₉N₃O: M⁺=565.31

4) Synthesis of Compound 5

2.9 g (5.13 mmol) of Intermediate 5-1, 2.5 g (6.16 mmol) of potassium tetrachloroplatinate, and 120 mL of acetic acid were added to a reaction vessel, and the mixture was stirred under reflux at a temperature of 120° C. for 16 hours. The reaction mixture was cooled to room temperature, and the organic layer was extracted therefrom using sodium hydrogen carbonate and 300 mL of ethyl acetate. The organic layer was dried over MgSO₄, and the solvent was removed therefrom by evaporation. The resulting residue was then separated and purified through silica gel chromatography to obtain 2.1 g of Compound 5 (yield: 55%). The compound thus obtained was identified by using LC-MS.

C₃₉H₃₇N₃OPt: M⁺=758.26

Synthesis Example 2 Synthesis of Compound 7

1) Synthesis of Intermediate 7-3

2 g (8.73 mmol) of 2-bromo-5-(trimethylsilyl)pyridine, 2.68 g (10.48 mmol) of (3-bromo-5-(tert-butyl)phenyl)boronic acid, 2.31 g (21.84 mmol) of Na₂CO₃, 0.7 g (0.07 mmol) of Pd(PPh₃)₄, 30 mL of toluene, 10 mL of H₂O, and 10 mL of ethyl alcohol (EtOH) were added to a reaction vessel, and the mixture was stirred under reflux at a temperature of 100° C. for 16 hours. The reaction mixture was cooled to room temperature, and the organic layer was extracted therefrom using 400 mL of water and 400 mL of ethyl acetate. The organic layer was dried over MgSO₄, and the solvent was removed therefrom by evaporation. The resulting residue was then separated and purified through silica gel chromatography to obtain 2.3 g of Intermediate 7-3 (yield: 74%). The compound thus obtained was identified by using LC-MS.

C₁₈H₂₄BrNSi: M⁺=361.09

2) Synthesis of Intermediate 7-2

Intermediate 7-2 was synthesized in substantially the same manner as in Synthesis of Intermediate 5-2, except that Intermediate 7-3 was used instead of Intermediate 5-3. The compound thus obtained was identified by using LC-MS.

C₂₄H₃₆BNO₂Si: NA⁺=409.26

3) Synthesis of Intermediate 7-1

Intermediate 7-1 was synthesized in substantially the same manner as in Synthesis of Intermediate 5-1, except that Intermediate 7-2 was used instead of Intermediate 5-2. The compound thus obtained was identified by using LC-MS.

C₃₂H₃₅N₃OSi: NA⁺=505.25

4) Synthesis of Compound 7

2.0 g (5.13 mmol) of Intermediate 7-1, 1.86 g (5.13 mmol) of PtCl₂(NCPh)₂, and 20 mL of benzonitrile were added to a reaction vessel, and the mixture was stirred under reflux at a temperature of 125° C. for 7 hours. The reaction mixture was cooled to room temperature, and benzonitrile was removed therefrom by evaporation. The resulting residue was separated and purified through silica gel chromatography to obtain 2.1 g of Compound 7 (yield: 58%). The compound thus obtained was identified by using LC-MS.

C₃₂H₃₃N₃OPtSi: NA⁺=698.20

Synthesis Example 3 Synthesis of Compound 24

Intermediate 24-1 was synthesized in substantially the same manner as in Synthesis of Intermediate 5-1, except that Intermediate 24-2 was used instead of Intermediate 5-2, and Intermediate B was used instead of Intermediate A. Compound 24 was synthesized in substantially the same manner as in Synthesis of Compound 5, except that Intermediate 24-1 was used instead of Intermediate 5-1. The compound thus obtained was identified by using LC-MS.

C₄₅H₄₁N₃OPt: M⁺=834.29

Synthesis Example 4 Synthesis of Compound 64

Intermediate 64-1 was synthesized in substantially the same manner as in Synthesis of Intermediate 5-1, except that Intermediate 64-2 was used instead of Intermediate 5-2, and Intermediate B was used instead of Intermediate A. Compound 64 was synthesized in substantially the same manner as in Synthesis of Compound 5, except that Intermediate 64-1 was used instead of Intermediate 5-1. The compound thus obtained was identified by using LC-MS.

C₃₈H₃₇N₃OPt: M⁺=746.26

Synthesis Example 5 Synthesis of Compound 65

Intermediate 65-1 was synthesized in substantially the same manner as in Synthesis of Intermediate 5-1, except that Intermediate 65-2 was used instead of Intermediate 5-2, and Intermediate B was used instead of Intermediate A. Compound 65 was synthesized in substantially the same manner as in Synthesis of Compound 5, except that Intermediate 65-1 was used instead of Intermediate 5-1. The compound thus obtained was identified by using LC-MS.

C₄₉H₄₄N₄OPt: NA⁺=899.32

Example 1

An ITO glass substrate was cut to a size of 50 millimeters (mm)×50 mm×0.5 mm. Then, the glass substrate was sonicated in acetone iso-propyl alcohol and pure water for about 15 minutes each, and cleaned by exposure to ultraviolet rays and ozone for 30 minutes.

Thereafter, a hole injection layer was formed to have a thickness of about 600 Å on the ITO electrode (anode) on the glass substrate by depositing m-MTDATA at a rate of about 1 Å/sec. A hole transport layer was formed to have a thickness of about 250 Å on the hole injection layer by depositing α-NPD at a rate of about 1 Å/sec.

An emission layer was formed to have a thickness of about 400 Å on the hole transport layer by co-depositing Compound 5 (as a dopant) and CBP (as a host) at a rate of about 0.1 Å/sec and 1 Å/sec, respectively.

A hole blocking layer was formed on the emission layer by depositing BAlq at a rate of 1 Å/sec to have a thickness of about 50 Å. Then, an electron transport layer was formed on the hole blocking layer by depositing Alq₃ to have a thickness of about 300 Å. An electron injection layer was formed on the electron transport layer by depositing LiF to have a thickness of about 10 Å. A second electrode (cathode) was formed on the electron injection layer by vacuum-depositing Al to have a thickness of about 1,200 Å. Therefore, the manufacture of an organic light-emitting device was completed, in which the organic light-emitting device included an ITO/m-MTDATA (600 Å)/α-NPD (250 Å)/CBP+10% Compound 5 (400 Å)/Balq (50 Å)/Alq₃ (300 Å)/LiF (10 Å)/Al (1,200 Å) structure.

Example 2

An organic light-emitting device was manufactured in substantially the same manner as in Example 1, except that Compound 7 was used instead of Compound 5 as a dopant in the formation of the emission layer.

Example 3

An organic light-emitting device was manufactured in substantially the same manner as in Example 1, except that Compound 24 was used instead of Compound 5 as a dopant in the formation of the emission layer.

Example 4

An organic light-emitting device was manufactured in substantially the same manner as in Example 1, except that Compound 64 was used instead of Compound 5 as a dopant in the formation of the emission layer.

Example 5

An organic light-emitting device was manufactured in substantially the same manner as in Example 1, except that Compound 65 was used instead of Compound 5 as a dopant in the formation of the emission layer.

Comparative Example 1

An organic light-emitting device was manufactured in substantially the same manner as in Example 1, except that PtOEP was used instead of Compound 5 as a dopant in the formation of the emission layer.

Evaluation Example 1 Evaluation of Characteristics of Organic Light-Emitting Device

The driving voltage, current efficiency, color-coordination, quantum efficiency, roll-off, and lifespan (T₉₅) of the organic light-emitting devices manufactured in Examples 1 to 5 and Comparative Example 1 were evaluated. The results thereof are shown in Table 2. A Keithley 2400 current voltmeter and a luminance meter (Minolta Cs-1000A) were used for the evaluation. The lifespan (T₉₅) refers to time required for the initial luminance of 6,000 nits of the organic light-emitting device to reduce by 95%. The roll-off was calculated by the following Equation 20:

Roll-off={1−(efficiency (at 9,000 nit)/maximum emission efficiency)}×100%   Equation 20

TABLE 2 Driving Current Quantum Roll Lifespan voltage efficiency efficiency off (T₉₅) Dopant (V) (cd/A) CIEx CIEy (%) (%) (hr) Example 1 5 5.5 33 0.60 0.40 17 15 100 Example 2 7 5.0 30 0.61 0.39 18.2 11 85 Example 3 24 5.1 50 0.64 0.34 27.5 9 180 Example 4 64 5.6 45 0.65 0.35 25.3 8 110 Example 5 65 5.4 47 0.66 0.34 24.2 10 125 Comparative PtOEP 7.3 22 0.67 0.32 15.2 9 80 Example 1

Referring to Table 2, the organic light-emitting device of Examples 1 to 5 were found to have excellent driving voltage, current efficiency, quantum efficiency, roll-off, and lifespan characteristics, as compared with the organic light-emitting device of Comparative Example 1.

As apparent from the foregoing description, the organometallic compound has excellent electrical characteristics and thermal stability. Accordingly, an organic light-emitting device employing the organometallic compound has a low driving voltage, high efficiency, high power, high color coordination, and excellent lifespan characteristics. Further, a diagnostic composition that includes the organometallic compound has high diagnostic efficiency, since the organometallic compound has excellent luminosity, particularly, excellent phosphorescent luminosity.

It should be understood that embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments.

While one or more embodiments have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present disclosure as defined by the following claims. 

What is claimed is:
 1. An organometallic compound represented by Formula 1:

wherein, in Formula 1, M₁₁ is selected from beryllium (Be), magnesium (Mg), aluminum (Al), calcium (Ca), titanium (Ti), manganese (Mn), cobalt (Co), copper (Cu), zinc (Zn), gallium (Ga), germanium (Ge), zirconium (Zr), ruthenium (Ru), rhodium (Rh), palladium (Pd), silver, (Ag), rhenium (Re), platinum (Pt), and gold (Au), T₁₁ is selected from oxygen (O) and sulfur (S), p11 is selected from 0 and 1; provided that when p11 is 0, *-Tr₁₁)_(p11)-*” is a single bond, T₁₂ to T₁₄ are each independently selected from nitrogen (N) and carbon (C), when p11 is 0, a bond between X₁₁ and M₁₁ is a covalent bond or a coordinate bond; when p11 is 1, a bond between T₁₁ and M₁₁ is a covalent bond, i) when p11 is 0, two bonds selected from a bond between X₁₁ and M₁₁, a bond between T₁₂ and M₁₁, a bond between T₁₃ and M₁₁, and a bond between T₁₄ and M₁₁ are each a covalent bond, and the other two bonds are each a coordinate bond; or ii) when p11 is 1, two bonds selected from a bond between T₁₁ and M₁₁, a bond between T₁₂ and M₁₁, a bond between T₁₃ and M₁₁, and a bond between T₁₄ and M₁₁ are each a covalent bond, and the other two bonds are each a coordinate bond, X₁₁ to X₁₈ are each independently selected from C and N, a bond between X₁₁ and X₁₂, a bond between X₁₃ and T₁₂, a bond between X₁₃ and Y₁₁, a bond between T₁₂ and X₁₄, a bond between X₁₄ and N, a bond between X₁₄ and X₁₅, a bond between Y₁₁ and N, a bond between X₁₆ and T₁₃, a bond between T₁₃ and X₁₇, and a bond between X₁₈ and T₁₄ are each independently selected from a single bond and a double bond, A₁₁, A₁₃, and A₁₄ are each independently selected from a C₅-C₃₀ carbocyclic group and a C₁-C₃₀ heterocyclic group, A₁₂ and A₁₅ are each independently selected from a C₁-C₃₀ heterocyclic group, L₁₁ to L₁₃ are each independently selected from *—O—*′, *—S—*′, *—[C(R₁₅)(R₁₆)]_(k11)—*40 , *—C(R₁₅)═*′, *═C(R₁₅)—*′, *—C(R₁₅)═C(R₁₆)—*′, *—C(═O)—*′, *—C(═S)—*′, *—C≡C—*′, *—N(R₁₅)—*′, *—P(R₁₅)—*′, *—[Si(R₁₅)(R₁₆)]_(k11)—*′, and *—P(R₁₅)(R₁₆)—*′, R₁₅ and R₁₆ are optionally bound via a first linking group to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group, k11 is selected from 1 and 2, a11 to a13 are each independently selected from 0, 1, 2, and 3; when a11 is 0, *-(L₁₁)_(a11)-*′ is a single bond; when a12 is 0, *-(L₁₂)_(a12)-*′ is a single bond; when a13 is 0, *-(L₁₃)_(a13)-*′ is a single bond, Y₁₁ is selected from N(R₁₇), N, C(R₁₇)(R₁₈), C(R₁₇), Si(R₁₇)(R₁₈), Si(R₁₇), and C(═O), R₁₇ and R₁₈ are optionally bound via a second linking group to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group, L₁₄ to L₁₇ are each independently selected from a substituted or unsubstituted C₅-C₃₀ carbocyclic group and a substituted or unsubstituted C₁-C₃₀ heterocyclic group, a14 to a17 are each independently selected from 0, 1, 2, 3, 4, and 5, R₁₁ to R₁₈ are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, —SF₅, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted C₁-C₆₀ heteroaryloxy group, a substituted or unsubstituted C₁-C₆₀ heteroarylthio group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), and —P(═O)(Q₈)(Q₉), b11 to b14 are each independently selected from 1, 2, 3, 4, and 5, n11 to n14 are each independently selected from 0, 1, 2, 3, 4, and 5, two adjacent groups R₁₁ of a plurality of groups R₁₁ are optionally bound to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group, two adjacent groups R₁₂ of a plurality of groups R₁₂ are optionally bound to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group, two adjacent groups R₁₃ of a plurality of groups R₁₃ are optionally bound to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group, two adjacent groups R₁₄ of a plurality of groups R₁₄ are optionally bound to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group, at least two of R₁₁ to R₁₄, wherein the at least two of R₁₁ to R₁₄ are adjacent to each other, are optionally bound to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group, wherein Q₁ to Q₉ are each independently selected from hydrogen; deuterium; —F; —Cl; —Br; —I; a hydroxyl group; a cyano group; a nitro group; an amidino group; a hydrazine group; a hydrazone group; a carboxylic acid group or a salt thereof; a sulfonic acid group or a salt thereof; a phosphoric acid group or a salt thereof; a C₁-C₆₀ alkyl group; a C₁-C₆₀ alkyl group substituted with at least one of deuterium, a C₁-C₆₀ alkyl group, and a C₆-C₆₀ aryl group; a C₂-C₆₀ alkenyl group; a C₂-C₆₀ alkynyl group; a C₁-C₆₀ alkoxy group; a C₃-C₁₀ cycloalkyl group; a C₁-C₁₀ heterocycloalkyl group; a C₃-C₁₀ cycloalkenyl group; a C₁-C₁₀ heterocycloalkenyl group; a C₆-C₆₀ aryl group; a C₆-C₆₀ aryl group substituted with at least one of deuterium, a C₁-C₆₀ alkyl group, and a C₆-C₆₀ aryl group; a C₆-C₆₀ aryloxy group; a C₆-C₆₀ arylthio group; a C₁-C₆₀ heteroaryl group; a monovalent non-aromatic condensed polycyclic group; and a monovalent non-aromatic condensed heteropolycyclic group, and * and *′ each independently indicate a binding site to an adjacent atom.
 2. The organometallic compound of claim 1, wherein a cyclometalated ring formed of A₁₅, A₁₂, A₁₃, and M₁₁ is selected from a 6-membered ring, a 7-membered ring, and an 8-membered ring.
 3. The organometallic compound of claim 1, wherein a cyclometalated ring formed of A₁₅, A₁₂, A₁₃, and M₁₁ is a 6-membered ring.
 4. The organometallic compound of claim 1, wherein p11 is 1, and a bond between T₁₁ and M₁₁ is a covalent bond.
 5. The organometallic compound of claim 1, wherein when p11 is 0, X₁₁ and T₁₂ are each C, T₁₃ and T₁₄ are each N, a bond between X₁₁ and M₁₁ and a bond between T₁₂ and M₁₁ are each a covalent bond, and a bond between T₁₃ and M₁₁ and a bond between T₁₄ and M₁₁ are each a coordinate bond; when p11 is 0, X₁₁ and T₁₄ are each C, T₁₂ and T₁₃ are each N, a bond between X₁₁ and M₁₁ and a bond between T₁₄ and M₁₁ are each a covalent bond, and a bond between T₁₂ and M₁₁ and a bond between T₁₃ and M₁₁ are each a coordinate bond; when p11 is 0, X₁₁ and T₁₃ are each C, T₁₂ and T₁₄ are each N, a bond between X₁₁ and M₁₁ and a bond between T₁₃ and M₁₁ are each a covalent bond, and a bond between T₁₂ and M₁₁ and a bond between T₁₄ and M₁₁ are each a coordinate bond; when p11 is 0, X₁₁ and T₁₂ are each N, T₁₃ and T₁₄ are each C, a bond between X₁₁ and M₁₁ and a bond between T₁₂ and M₁₁ are each a coordinate bond, and a bond between T₁₃ and M₁₁ and a bond between T₁₄ and M₁₁ are each a covalent bond; when p11 is 0, X₁₁ and T₁₄ are each N, T₁₂ and T₁₃ are each C, a bond between X₁₁ and M₁₁ and a bond between T₁₄ and M₁₁ are each a coordinate bond, and a bond between T₁₂ and M₁₁ and a bond between T₁₃ and M₁₁ are each a covalent bond; when p11 is 0, X₁₁ and T₁₃ are each N, T₁₂ and T₁₄ are each C, a bond between X₁₁ and M₁₁ and a bond between T₁₃ and M₁₁ are each a coordinate bond, and a bond between T₁₂ and M₁₁ and a bond between T₁₄ and M₁₁ are each a covalent bond; when p11 is 1, T₁₂ is C, T₁₃ and T₁₄ are each N, a bond between T₁₁ and M₁₁ and a bond between T₁₂ and M₁₁ are each a covalent bond, and a bond between T₁₃ and M₁₁ and a bond between T₁₄ and M₁₁ are each a coordinate bond; when p11 is 1, T₁₄ is C, T₁₂ and T₁₃ are each N, a bond between T₁₁ and M₁₁ and a bond between T₁₄ and M₁₁ are each a covalent bond, and a bond between T₁₂ and M₁₁ and a bond between T₁₃ and M₁₁ are each a coordinate bond; or when p11 is 1, T₁₃ is C, T₁₂ and T₁₄ are each N, a bond between T₁₁ and M₁₁ and a bond between T₁₃ and M₁₁ are each a covalent bond, and a bond between T₁₂ and M₁₁ and a bond between T₁₄ and M₁₁ are each a coordinate bond.
 6. The organometallic compound of claim 1, wherein X₁₂ to X₁₈ are each C.
 7. The organometallic compound of claim 1, wherein A₁₁, A₁₃, and A₁₄ are each independently selected from a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, a triphenylene group, a pyrene group, a chrysene group, a cyclopentadiene group, a 1,2,3,4-tetrahydronaphthalene group, a furan group, a thiophene group, a silole group, an indene group, a fluorene group, an indole group, a carbazole group, a benzofuran group, a dibenzofuran group, a benzothiophene group, a dibenzothiophene group, a benzosilole group, a dibenzosilole group, an indenopyridine group, an indolopyridine group, a benzofuropyridine group, a benzothienopyridine group, a benzosilolopyridine group, an indenopyrimidine group, an indolopyrimidine group, a benzofuropyrimidine group, a benzothienopyrimidine group, a benzosilolopyrimidine group, a dihydropyridine group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a phenanthroline group, a pyrrole group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, a thiazole group, an isothiazole group, an oxadiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzothiazole group, a benzoxadiazole group, a benzothiadiazole group, a 5,6,7,8-tetrahydroisoquinoline group, and a 5,6,7,8-tetrahydroquinoline group, and A₁₂ and A₁₅ are each independently selected from an indole group, a carbazole group, an indenopyridine group, an indolopyridine group, a benzofuropyridine group, a benzothienopyridine group, a benzosilolopyridine group, a dihydropyridine group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a phenanthroline group, a pyrrole group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, a thiazole group, an isothiazole group, an oxadiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzothiazole group, a benzoxadiazole group, a benzothiadiazole group, a 5,6,7,8-tetrahydroisoquinoline group, and a 5,6,7,8-tetrahydroquinoline group.
 8. The organometallic compound of claim 1, wherein A₁₁, A₁₃, and A₁₄ are each independently selected from a benzene group, a naphthalene group, a 1,2,3,4-tetrahydronaphthalene group, a dibenzofuran group, a dibenzothiophene group, a benzofuropyridine group, a benzothienopyridine group, a benzofuropyrimidine group, a benzothienopyrimidine group, a dihydropyridine group, a pyridine group, a quinoline group, an isoquinoline group, a pyrrole group, an imidazole group, a benzimidazole group, a 5,6,7,8-tetrahydroisoquinoline group, and a 5,6,7,8-tetrahydroquinoline group, and A₁₂ and A₁₅ are each independently selected from a dihydropyridine group, a pyridine group, a quinoline group, an isoquinoline group, a pyrrole group, an imidazole group, a 5,6,7,8-tetrahydroisoquinoline group, and a 5,6,7,8-tetrahydroquinoline group.
 9. The organometallic compound of claim 1, wherein Y₁₁ is selected from N and C(R₁₇).
 10. The organometallic compound of claim 1, wherein L₁₄ to L₁₇ are each independently selected from a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, a triphenylene group, a pyrene group, a chrysene group, a cyclopentadiene group, a furan group, a thiophene group, a silole group, an indene group, a fluorene group, an indole group, a carbazole group, a benzofuran group, a dibenzofuran group, a benzothiophene group, a dibenzothiophene group, a benzosilole group, a dibenzosilole group, an indenopyridine group, an indolopyridine group, a benzofuropyridine group, a benzothienopyridine group, a benzosilolopyridine group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a phenanthroline group, a pyrrole group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, a thiazole group, an isothiazole group, an oxadiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzothiazole group, a benzoxadiazole group, and a benzothiadiazole group; and a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, a triphenylene group, a pyrene group, a chrysene group, a cyclopentadiene group, a furan group, a thiophene group, a silole group, an indene group, a fluorene group, an indole group, a carbazole group, a benzofuran group, a dibenzofuran group, a benzothiophene group, a dibenzothiophene group, a benzosilole group, a dibenzosilole group, an indenopyridine group, an indolopyridine group, a benzofuropyridine group, a benzothienopyridine group, a benzosilolopyridine group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a phenanthroline group, a pyrrole group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, a thiazole group, an isothiazole group, an oxadiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzothiazole group, a benzoxadiazole group, and a benzothiadiazole group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, a triazinyl group, a fluorenyl group, a dimethylfluorenyl group, a diphenylfluorenyl group, a carbazolyl group, a phenylcarbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a dimethyldibenzosilolyl group, a diphenyldibenzosilolyl group, —N(Q₃₁)(Q₃₂), —Si(Q₃₃)(Q₃₄)(Q₃₅), —B(Q₃₆)(Q₃₇), and —P(═O)(Q₃₈)(Q₃₉), wherein 0₃₁ to 0₃₉ are each independently selected from —CH₃, —CD₃, —CD₂H, —CDH₂, —CH₂CH₃, —CH₂CD₃, —CH₂CD₂H, —CH₂CDH₂, —CHDCH₃, —CHDCD₂H, —CHDCDH₂, —CHDCD₃, —CD₂CD₃, —CD₂CD₂H, and —CD₂CDH₂; an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, and a naphthyl group; and an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, and a naphthyl group, each substituted with at least one selected from deuterium, a C₁-C₁₀ alkyl group, and a phenyl group.
 11. The organometallic compound of claim 1, wherein R₁₁ to R₁₈ are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, —SF₅, a C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group; a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₁₀ alkyl group, a cyclopentyl group, a cyclopentyl group substituted with deuterium, a cyclohexyl group, a cyclohexyl group substituted with deuterium, a cycloheptyl group, a cycloheptyl group substituted with deuterium, a cyclooctyl group, a cyclooctyl group substituted with deuterium, a bicyclo[2.2.1]heptanyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a naphthyl group, a pyridinyl group, and a pyrimidinyl group; a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a bicyclo[2.2.1]heptanyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, and an imidazopyrimidinyl group; a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a bicyclo[2.2.1]heptanyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a naphthyl group, a tluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, an isobenzolhiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzoturanyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, and an imidazopyrimidinyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereol, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclopentyl group substituted with deuterium, a cyclohexyl group, a cyclohexyl group substituted with deuterium, a cycloheptyl group, a cycloheptyl group substituted with deuterium, a cyclooctyl group, a cyclooctyl group substituted with deuterium, a bicyclo[2.2.1]heptanyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, and —Si(Q₃₃)(Q₃₄)(Q₃₅); and —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —B(Q₈)(Q₇), and —P(═O)(Q₈)(Q₉), wherein Q₁ to Q₉ and Q₃₃ to Q₃₅ are each independently selected from —CH₃, —CD₃, —CD₂H, —CDH₂, —CH₂CH₃, —CH₂CD₃, —CH₂CD₂H, —CH₂CDH₂, —CHDCH₃, —CHDCD₂H, —CHDCDH₂, —CHDCD₃, —CD₂CD₃, —CD₂CD₂H, and —CD₂CDH₂; an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, and a naphthyl group; and an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, and a naphthyl group, each substituted with at least one selected from deuterium, a C₁-C₁₀ alkyl group, and a phenyl group.
 12. The organometallic compound of claim 1, wherein R₁₁ to R₁₈ are each independently selected from hydrogen, deuterium, —F, a cyano group, a nitro group, —SF₅, a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, an n-hexyl group, an iso-hexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an iso-heptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an iso-octyl group, a sec-octyl group, a tert-octyl group, an n-nonyl group, an iso-nonyl group, a sec-nonyl group, a tert-nonyl group, an n-decyl group, an iso-decyl group, a sec-decyl group, a tert-decyl group, a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a penloxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a bicyclo[2.2.1]heptanyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, a fluorenyl group, a carbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, and a dibenzosilolyl group; a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, an n-hexyl group, an iso-hexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an iso-heptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an iso-octyl group, a sec-octyl group, a tert-octyl group, an n-nonyl group, an iso-nonyl group, a sec-nonyl group, a tert-nonyl group, an n-decyl group, an iso-decyl group, a sec-decyl group, a tert-decyl group, a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a bicyclo[2.2.1]heptanyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, a lluorenyl group, a carbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, and a dibenzosilolyl group, each substituted with at least one selected from deuterium, —F, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a cyano group, a nitro group, a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a cyclopentyl group, a cyclopentyl group substituted with deuterium, a cyclohexyl group, a cyclohexyl group substituted with deuterium, a cycloheptyl group, a cycloheptyl group substituted with deuterium, a cyclooctyl group, a cyclooctyl group substituted with deuterium, a bicyclo[2.2.1]heptanyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, a fluorenyl group, a carbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, and —Si(Q₃₃)(Q₃₄)(Q₃₅); and —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), and —P(═O)(Q₈)(Q₉). wherein Q₁ to Q₉ and Q₃₃ to Q₃₅ are each independently selected from —CH₃, —CD₃, —CD₂H, —CDH₂, —CH₂CH₃, —CH₂CD₃, —CH₂CD₂H, —CH₂CDH₂, —CHDCH₃, —CHDCD₂H, —CHDCDH₂, —CHDCD₃, —CD₂CD₃, —CD₂CD₂H, and —CD₂CDH₂; an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, and a naphthyl group; and an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, and a naphthyl group, each substituted with at least one selected from deuterium, a C₁-C₁₀ alkyl group, and a phenyl group.
 13. The organometallic compound of claim 1, wherein R₁₁ to R₁₈ are each independently selected from hydrogen, deuterium, -F, a cyano group, a nitro group, —SF₅, —CH₃, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, groups represented by Formulae 9-1 to 9-21, groups represented by Formulae 10-1 to 10-246, —N(Q₁)(Q₂), —Si(Q₂)(Q₄)(Q₅), —B(Q₆)(Q₇), and —P(═O)(Q₈)(Q₉):

wherein Q₁ to Q₉ are each independently selected from —CH₃, —CD₃, —CD₂H, —CDH₂, —CH₂CH₃, —CH₂CD₃, —CH₂CD₂H, —CH₂CDH₂, —CHDCH₃, —CHDCD₂H, —CHDCDH₂, —CHDCD₃, —CD₂CD₃, —CD₂CD₂H, and —CD₂CDH₂; an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, and a naphthyl group; and an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, and a naphthyl group, each substituted with at least one selected from deuterium, a C₁-C₁₀ alkyl group, and a phenyl group, in Formulae 9-1 to 9-21 and 10-1 to 10-246, * indicates a binding site to an adjacent atom, the term “i-Pr” represents an iso-propyl group, the term “i-Bu” represents an iso-butyl group, the term “t-Bu” represents a t-butyl group, the term “Ph” represents a phenyl group, the term “1-Nph” represents a 1-naphthyl group, the term “2-Nph” represents a 2-naphthyl group, the term “2-Pyr” represents a 2-pyridyl group, the term “3-Pyr” represents a 3-pyridyl group, the term “4-Pyr” represents a 4-pyridyl group, and the term “TMS” represents a trimethylsilyl group.
 14. The organometallic compound of claim 1, wherein the organometallic compound is represented by any one of Formulae 1-1 to 1-4:

wherein, in Formulae 1-1 to 1-4, M₁₁, T₁₁, Y₁₁, L₁₁ to L₁₇, a11 to a17, R₁₁ to R₁₄, b11 to b14, and n11 to n14 are the same as those defined with reference to Formula
 1. 15. The organometallic compound of claim 1, wherein the organometallic compound is selected from Compounds 1 to 89:

wherein in Formulae 1 to 89, the term “TMS” represents a trimethylsilyl group.
 16. An organic light-emitting device comprising: a first electrode; a second electrode; and an organic layer disposed between the first electrode and the second electrode, wherein the organic layer comprises an emission layer and at least one organometallic compound of claim
 1. 17. The organic light-emitting device of claim 16, wherein the first electrode is an anode, the second electrode is a cathode, and the organic layer comprises a hole transport region disposed between the first electrode and the emission layer and an electron transport region disposed between the emission layer and the second electrode, wherein the hole transport region comprises at least one of a hole injection layer, a hole transport layer, and an electron blocking layer, and wherein the electron transport region comprises at least one of a hole blocking layer, an electron transport layer, and an electron injection layer.
 18. The organic light-emitting device of claim 16, wherein the emission layer comprises the organometallic compound.
 19. The organic light-emitting device of claim 18, wherein the emission layer further comprises a host in an amount of greater than an amount of the organometallic compound.
 20. A diagnostic composition comprising at least one of the organometallic compound of claim
 1. 